Don't over think flies as they seldom truly matter. Choose patterns you have the most confidence in and put them where the fish are and you'll catch fish. Sure, there are times when a big, wild brown is finicky during the hatch and the fly becomes critical, but those are the exceptions to the rule. There's a good reason why some swear by nymphs, others dries, others wets, and yet other streamers. All are effective to trigger the feeding response. The key with any of those is presentation first, color and size second. Trout have an equivalent IQ of 6; they don't think, they respond.
My advice is to stick with the staples and try some new flies if they aren't working for you or if you notice something about the feeding instincts while on the river that you need to mimic back home at your vice.