Re: Best small stream flies?
Welcome to the forum,
The question could be as simple as taking some Elk Hair Caddis and some Adams patterns along the next trip to the stream and looking for what else is hatching there. Picking up a copy of Art Flick's Stream Side Guide to Natural Insects and Their Imitations will be a great help to you.
You don't have to be able to identify every Mayfly or Caddis you see but it is good to understand what you are seeing and how to imitate it. The book will help.