It's never a bad idea to take a peek over your shoulder occasionally, fish have a nasty little habit of creeping up in your blind spots. Concentration is another key ingredient. The moment you start daydreaming is when the fish bump into the side of the boat. I'm often asked how far from the boat I concentrate my search. This varies with conditions - on a sunny day it may be one hundred yards, while on a cloudy day, only a boat length or two.
Poor visibility makes the most demands on both the angler and the guide.
Short, quick casts are the norm, you just won't have the time for anything else. It's a good idea to look behind the boat as your guide starts across a new flat to see what color the mud is as it comes off his pushpole. That will be exactly the same color as the muds the fish make on that particular flat. Carefully check out any motion you see on the flat. Bonefish and permit are rarely static and the motion as they swim is often easier to spot than the fish themselves.