Seining is my favorite method to catch hellgrammites (dobsonfly larvae) and one of my favorite methods to catch crayfish. I take my framed seine net into the rapids, push it into the rocks, and rustle the rocks and gravel upstream with my boots. This trip, I was catching hellgrammites at a rate of about 60/hour and crayfish at a rate of about 420/hour. I catch hellgrammites and crayfish for bait fishing for most local river species: smallmouth bass, walleye, pike, carp, catfish, panfish, and more.
For more outdoors tips and tricks I've learned, check out the rest of my How To Fishing and Hunting series.