I recommend just getting a 1/4" cast net. Easier to use for 1 person and catches minnows no problem. Go to a local creek and throw it in a shallow gravel ripple and you should get plenty of red shiners, which are crappie candy.

I seined a lot in Mississippi and Louisiana when I worked as a biologist - not just for bait, but to "sample" what was in the shallow water. When seining in running water you have to move downstream - otherwise you are fighting the current and most of your catch will get away. When minnows were scarce we would push a handful of corn meal into the bottom and wait a few minutes to catch a bunch. Move as fast as you can while making sure the lead line stays at the bottom. Make a "J" with the short leg at the bank - move along the bank a ways then the deeper (longer)leg comes to shore. A 14-16 foot seemed optimum for us - longer ones catch more fish/minnows but are hard to pull and harder to beach without a lot of practice and coordination between the net pullers.