You had the right idea about the moving water and the deeper pools. The fish feel safer in the broken water and deeper pools. I prefer to euro nymph these places and really like to short line the broken water. Don't bypass the white water either even though it seems really fast the fish will hold there. I usually start out with a heavy stonefly nymph to get down in the fast water and then when I'm done with that pocket I'll hold my net down stream of some rocks and kick them over to see what I end up with in my net. I then base what flies I use from there. Don't forget when the water is low and the sun is high in the sky you can't be to stealthy.