To Catch Crayfish: According to an old-time fisherman, set out four or five drop nets up and down the river at night.  Bait them with bacon and dog food (in small mesh bags placed in the center of the nets).  You may need to weigh the nets down and mark their location with some kind of floating device.  Check them after a few hours.  Some would claim they are as good as shrimp.

To Catch Minnows:  Bait the net with some kind of crumbs (again, in a mesh bag attached in the center of the net).

To Bait Net: Make up a flour & water paste and spread it on the net. Let dry well, then use.