I don't know how much certain things really help or not, but here are a few things I do that I truly believe make a difference:
1) Line diameter - I usually go bigger than I should, but know smaller is more productive (I'm just scared of breaking off a big one)
2) Underwater Noise (thumps in the boat - noises that will be picked up by a fishes lateral line). A good example is a trolling motor or depth finder. We have an ongoing debate which is louder, my trolling motor or outboard. Yes, something is wrong with my trolling motor. However, I think it just may be a brand thing and they are so pricey to replace...
3) Clothes - you may think I'm crazy, but I truly believe not wearing white or bright colored colors makes a difference when fishing less than 20'.
4) Boats - try and stay as far away from your target as possible. This is just a belief, however, it has been proven wrong so many times I don't know why I believe it. I've bumped trees, flipped 2 feet from the boat and still caught quality fish. Whatever, I think they do it just to mess with my head.
5) Slow down. I don't know if this is universal, but for me, slowing down my presentation, and picking apart an area has produced good results.
6) Last but not least, the splash. Even though I have literally thrown right on top of a fish and had them strike the bait, I believe overall greater success can be achieved with a quiet entry, preferably not directly on top of the fish.
Please share any bits of wisdom, proven or otherwise. Tide, wind, current, colors, scents, etc... One thing I would be curious is if anyone has any indicators they use (certain birds, turtles, shad blowing up
Have a safe Memorial Weekend.