I use a piece of window screen about 24" x 24". Find some fast moving water in a very rocky area. Wedge the screen between two rocks about 12" apart and raise the back. Go about 10' upstream of the screen and start turning over rocks using your hands and feet. Keep an open eye for hellgramites on the bottom of the rocks. The current will wash everything through the screen leaving 'mites, nympts, crawfish, and minnows. The big 'mites with the red head are killer.You can net the Helgies in fast water below the dam.