On a stream for me, the most successful spots are under edges of banks, especially if they have grass or tree roots over them. It gives them cover and food travels in the currents is trapped along the bank for easy picking.
Also, learn to "read" the stream. Trout like to put themselves near or in currents where food is brought to them so they don't have to chase. Take a small bobber tied to the end of a line (w/no hook) and just toss it into the water. Watch where it goes and you have a better idea of how the current carries insects down the stream. Then follow what Ghostbear said! Good luck![up]