That is a bit too general of a question. It depends on where you are fishing and what time of day. I tell you trico spinners are the ticket and you never fish before 5pm....won't help you a bit.
Ants, crickets and beetles seem to always provide rises in the summer. If the water you are fishing has iso, craneflies, Cahills, tricos, etc...all good choices. Learn what hatches are on the water you fish. Some hatch at first light, some mid morning and some are at last light. For streamer fishing, #2-#4 sculpin has produced well for me over the years. Brookie fishing in the mountains, cigarette butt on a hook will work.
If you give a specific stream or area, you may get more useful info.