Streamers are definitely my favorite kind of fly to tie. I don't normally go by any set design, though. I normally tie them in natural patterns to imitate the exact forage species in a certain water or a tie them very flashy just to get the attention of the fish. 1-2" Clousers and bucktail patterns are among my favorites for inland trout and I use 4-6" monster sized ones made of flash, tinsel, bucktail, etc for big Lake Trout in Erie.
I love fishing nymphs and dries too, I just suck at tying them!