Trout Flies | A Guide To Logical Selection

When you look at the vast array of trout flies that are available today it would be safe to assume that trout will in fact eat anything and the process of fly selection is just as important for the enjoyment of the angler as it is a means for fooling a fish. No doubt the greatest driver of all of these weird and wacky fly designs available is the endless theories and beliefs held by all anglers about their favourite flies and what works for them.

In this article, I’d like to suggest we move past the emotional ties of our favourite patterns and discover the variables that sit behind intelligent fly design and why using the logical pattern of decision-making below can help us to better solve on-the-water fly selection decisions, and as a result, fool more trout.

  • Sink Rate
  • Flash
  • Colour
  • Movement
  • Size
  • Realism

I must confess from the onset to readers that when it comes to abnormally large fly collections I am without question one of the worst offenders. In fact, my obsession has now become so bad that I've had to rent a warehouse, employ staff and enlist manufacturers and fly designers to assist. Although my obsession is without question at times emotionally guided I'd like to discuss the process of selecting trout flies from a non-emotional and hopefully logical standpoint.

I'm sure we'd all like to believe that our fly selection decisions are fully rational and emotionally detached, however, even the Greek philosopher Plato highlighted that “all learning has an emotional base”. As anglers, it's easy for us to get caught up in the trout flies that we have become confident in from past experience, the ones that drawback great memories of fish caught and stellar days on the water and as a result avoid those that have failed to work in the whether the differentiation between the two is logical or not.

Motivational speaker, Tony Robbin’s message is that our beliefs are anchored by good and/or bad experiences. Of course this is the foundation for basic learning we try something it works so we try and replicate that success time and time again. The issue is what happens on the water isn’t consistent and our quarry the trout can be highly unpredictable, so by sticking to the formula of what worked yesterday we can be limiting ourselves on what the reality is today.


Choosing trout flies for fly fishing

Before we start on what a logical pattern of selection is I think it’s important to identify the weakness of our own experiences and how in fact they can at times limit good decision-making in the future. The biggest failure for all of us is how we trial new trout flies.

More often than not we will start the day with one of our trusted flies; statistics would show that for nymph fishers this is either a pheasant tail or hare and copper derivative. If we are catching fish then we will stick with our favourite fly but if we are not catching fish then this is the stage we start to try something new. If the new pattern works we lock it into our set of favourites, if however it doesn't then it gets relegated to the section of patterns that don't work. This trial of course is far from scientific, by trialling a new pattern when we aren't catching fish is for the most part setting the fly up for failure, and secondly, by labelling a pattern as one that doesn't work from such a poor trial is a waste of a potentially great pattern.

There are two solutions to this dilemma; the first is that we stick to the tried and true patterns, persevering until it produces the results. All in all this isn’t a silly idea as we all know the primary factor in success is of course presentation and by limiting ourselves to just a few patterns at least we can dedicate our focus to that task.

The second, more fun and I'd like to suggest most effective method is to learn the logical processes to choosing your trout flies to understand what variables are worth changing and how to select a better range of flies to solve your on-the-river problems - and when combined with great presentation and line control you then have the formula for catching more fish.


The first thing we all think about when it comes to choosing our trout flies is of course what are the fish feeding on? That is important but here’s another question to add into the mix, can I get them to eat what I’m offering? More often than not our fish are feeding on a particular food source but not selectively, so the question of what they are feeding on is more often than not irrelevant. What’s more important to be thinking about is how am I going to best target this fish and get it to notice and eat my fly.

Royal Wulff Fly

Royal Wulff

Another way of looking at this is to make a fly choice primarily with presentation in mind rather than representation. A classic example of such a fly is the well known Royal Wulff, let’s be honest here a Royal Wulff looks like no insect alive; firstly the tail is too thick (I’m yet to see an insect dressed with a red cummerbund and those white wings are as close to nature as the latest celebrity boob job). That said, Royal Wulff’s catch fish. In fact, I carry them in a bunch of different sizes and even tie a variant with a black hackle which I convinced myself would be more effective on fish that had seen too many of the originals (a classic example of an emotional decision that makes no sense). What makes a Royal Wulff such a great fly is it’s highly visible with those big white wings, it’s fairly easy to tie and it floats well, in fact well enough to be able to hold up a nymph if you want to fish a dry/dropper rig.

So if those are the reasons we like a Royal Wulff then let’s have a think about those variables and what other patterns may be of use. When it comes to buoyancy, as we mentioned, the Royal Wulff is good but nowhere near as good as the more modern foam-based flies around, so if you’re fishing riffle water I‘m sure you’d find an improved humpy with its foam back more buoyant that the traditional wulff. As for visibility? Yes the wulffs are good but in some light it’s difficult to see the white wings and a high visibility orange like a Hi Viz PMX will stand out a lot better.

Overall there are a huge number of factors that should be considered in picking our trout flies and asking ourselves good questions like “what am I expecting this fly to do” and “of the flies in my box which ones will perform best” are a great start towards making better decisions.


Often the factors determining good fly selection such as buoyancy and profile are more to do with presentation than what trout flies actually look like. With presentation in mind let’s have a think about how this would dictate our selection of a nymph.

With nymphs, the primary factor that affects presentation is sink rate. Of course sink rate is determined by the fly’s weight, but more importantly by the overall density of the fly as a whole. A buggy hare a copper with a fluffy dubbed body will sink slower than a pheasant tail of the same weight as the bulkier tie of the hare and copper reduces the flies overall density.

With all of this in mind, I like to carry a wide range of nymphs in different sink rates, some are tied super slim and super heavy to give me a maximum sink rate whilst others are tied with less weight and a bulkier body to slow down the sink rate.

The importance of this was reminded to be a few years back when I had a weekend stalking the edges of a lake for cruising browns. The fish were found feeding in between one and four feet of water, even an unweighted slimly tied pattern would plummet to the bottom too quickly and fall out of sight of the cruising fish. What we had to use were unweighted but bushy little nymphs that would sink slowly through the water column giving the fish enough time to find them. Despite by numerous collections of flies I didn’t have such a pattern and had to steal some from a more educated friend.

Simon's Ugly Fly

Simon's Ugly

As a contrast, when river fishing I always carry with me some extremely heavy flies like Simon Chu’s Uglies which have two large tungsten beads on them to really get down when it’s needed.


Although I’ve obsessed so far about how the fly will actually be presented to the trout of course what the fly looks like is also important. This also can be broken down into a number of simple variables like colour, flash, movement, size, shape and realism all of which can make the difference between catching fish and not.

Firstly flash, when most of us look at flashy flies, or even nymphs with flashbacks or sparkly dubbing, it is easy to see these as attractor, unnatural type patterns but of course in nature flash is quite common, be it from the flashy size of a baitfish like a smelt or inanga or the subcutaneous air bubbles that develop on nymphs to help them ascend through the water column. I’ve certainly had times when both browns and rainbows have been suckers for flies with flash, at one stage I wouldn’t fish a streamer unless it at least had a few strands of flashabou in the tail.

That was all until I fished in a national championships held on the Wheao Canal a number of years back. In practice I had caught plenty of fish on small flashy woolly buggers, so on competition day I fished these religiously with only one fish caught in the first two and three quarter hours of my three hour session. As I’d done so well on the flashy little buggers before I felt I had the flies figured out and my lack of success was because I’d drawn a bad beat. As the last quarter of an hour rolled around for some reason I made a fly change and put on a classic big black woolly bugger with no flash. The result was instant and in the next fifteen minutes I landed 3 more fish. In hindsight had I not been so pigheaded on my fly selection I could have done a lot better. To summarise on flash, make sure you’ve got some flashy flies and some without.


Tom Hodge South Island Fly Fishing Guide

Of course the most obvious variable in fly patterns is their colour. I’d always fished flies in either black, brown, or olive until a number of years ago I was introduced to blue-coloured nymphs by a popular south island guide. These days it’s common knowledge that pink and purple flies are killers on spawning rainbows, red flies, in general, seem to work year-round in all of our rivers and even our most wary of south island trout seem to respond to some striking colours like lime green stoneflies through to the bling flies that are promoted by anglers like Simon Chu and Chris Dore.

For me I like colour and at all times try and stock my box with plenty of it, I also try and make sure I have plenty of both light and dark patterns. A tip I had heard a long time ago which I have found useful is to fish one dark fly and one light, that way depending on the background the fish was going to see the flies against one would show up better. These days I tend to extend that habit into fishing one natural coloured pattern and one bright and flashy fly, that way I get the best of both worlds.


A variable that I have always found important, especially in streamers, is movement. Arguably the two groups of streamers with the best movements are rabbit-style flies and woolly buggers. Both of which have plenty of built-in movement and can be tied in such a variety of ways is important. I also try and tie some classic style patterns using features pulled from a traditional rabbit or woolly bugger pattern.

For example, a Red Setter has always been a great pattern but in my mind it can be improved by transferring those colours across to a woolly bugger, i.e. swap out the lifeless squirrel tail for black marabou and by changing the two collar hackles for a nicely palmered hackle like a woolly bugger.

Similarly, killer flies can be improved by adding marabou tails and as they are a bully or baitfish pattern then why not add eyes just like all of the great smelt patterns that have been popularised by Rotorua’s Pat Swift.

Mike Davis Backcountry Stonefly

Davis Backcountry Stonefly

When it comes to nymphs unless I want the fly to sink super quick I will always try and add legs for movement with either hackle tips or rubber legs. I’ve found long rubber legs to be particularly effective at times with flies like Mike Davis’s Backcountry Stoneflies which when drifted through large slower pools seem to outfish flies with less movement.


If there were one variable that I believe has the most effect on one’s success then I would choose fly size, and interestingly I find that often this is the one least tried. I’ve discussed before the value of becoming confident in fishing tiny flies in sizes 18 and below and I believe of equal importance is trying larger patterns like big #2 streamers on rivers that you would have previously only fished with a small nymph.

The most important thing overall is that you get used to changing the size of your flies whenever you aren’t having success, I’ve found scaling my fly size both up and down has been all it takes to turn apparently uncatchable fish into takers.


The last variable in fly design is whether you go for a realistic or impressionistic pattern. If we bring it back to our friend the Royal Wulff, which of course looks like nothing that nature has ever created yet proves to be effective time and time again, we could be led to believe that realism is not important. However, I have found over recent years that some of the more realistic patterns tied by the likes of Taranaki’s Kyle Adams or Blenheim’s Clayton Nichol are at times the key to heavily fished to, or selective fish.


Although I am a firm believer in the development of a sixth sense in this sport I also believe when it comes to choosing trout flies it’s important to balance our gut feel with the understanding of a number of principles that can lead to better decision making and results on the water.

To finish where we started, all flies work, and whether you are an avid fly tier or an eager purchaser of flies the sky is without question the limit when it comes to fly design and selection.

By understanding the basic principles we've outlined and utilising a broad range of different patterns we are able to better understand the variables that truly make a difference on the water. As preparation, my suggestion is there is a lot of value at looking to stock your box with a range of fly patterns that will lead to more options on the water, making sure you have options of colours, flash, weight, size, shape and movement in your trout flies so when you are standing streamside wanting to know what to tie on next your fly box doesn't just show endless duplication of the same thing, but rather shows you some serious options to really produce some results.


Rene Vaz, Manic Tackle Project founder, got his start as a school kid tying flies for tackle stores. By the time he’d reached University to study fisheries biology he was working in one of those stores, writing and photographing for the leading Australasian fishing magazines, competing as the youngest member of the NZ fly fishing team and teaching fly casting on the rugby field close to his house.