What follows is pretty obvious, but still gets all of us from time to time.

One thing you have to watch out for are preconceived notions about a bass fishing trip.

I know how it happens. You've been fishing this particular lake/pond/spot for years, or just the same place for a few weeks in a row.

You are 'dialed in' to where the fish are, what they want, and you know how to catch them.

You've been pretty successful at it, and so you grab the rod rigged with whatever it is you've been taking fish on, and head out to catch another bunch of bass...maybe you actually just grab a ready rigged rod and put a small box of flies in your shirt pocket...

You get there, and things have changed. Maybe the weather, maybe the water level, water clarity, water temperaure. Something is different, and the bass aren't cooperating.

After a bit of trying the 'fly/technique/pattern' that was working so well, you realize that the fish have moved. Shallower, deeper, into or out of cover, but they aren't where they 'should' be and you don't have what it will take to get them. You left the 'sinking/floating/intermediate' line that you need at home. You didn't bring the heavy 'bottom bouncer' flies with you (or the topwater flies, or the whichever you believe will work 'now').

Bass can be tricky in this regard. You can't carry everything, but be pepared to have to change your approach occasionally. Most bites are tansitory, and you need to be able to adapt to the fish.

Good Luck!