Nate, ... SC has some great comments.
I think (IMHO), the more you chase after these beasts, the more you 'll learn that there aren't any rules 'cept :
1)respect the Salmon and
2)respect your fellow angler.
Other than that, there are lots of THEORIES, the rest is time on the water.
Case in point. Many switch to dries near the end of the day. I like to try some dries on a few pools during the mid day lunch break. 'ya never know ...