Change your knots often. When tightened, your knot stretches and stresses your tippet material. The longer it remains in this stretched state, the weaker it becomes. You only have to leave a tippet tied on overnight to give it a pull the next day and see how easily your knot gives way. I change my knots every hour or so, even if i have not made a cast, more so if I am constantly working the water. It’s just what I do. This way my leader system is the strongest it can be and if I break off a fish, so be it. We all lose fish due to knots breaking, that’s life. But if it’s a freshly tied and tested knot, then I at least know that I've done everything I can to ensure I am fishing with the strongest connection possible, and there was little more I could do.