One thing I often find with budding spey casters is the inability to use the bottom hand effectively. It's the bottom hand that moves the rod tip: the top hand is but a pivot to allow effective use of the lever. Many stop the tip of their rod way too vertical when setting the cast, maybe a Hang up from the default 30' single hand backcast stop position they employ for much of the year.
This doesn't leave you with a lot of time to accelerate the cast, pull it through and really bring that bottom hand into play, instead resulting in the angler 'pushing' their rod forward and employing their top hand a little too much to compensate.
The solution? Set your D, stopping that rod tip a little further back: around 1.30 should do it with skagit and Scandi type heads. You are now set for a more effective stroke which will allow your bottom hand to work its magic, resulting in a much more efficient cast.
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