The crawfish traps that are commonly used by non-commercial types is a 4 cornered net spread by 2 wires bent over to opposite corners and tied together at the top. You set out about a dozen with bait (chicken parts or fish bait in the middle.

Now get your fishing pole and a beer and an empty cooler. Have a drink of beer, use the pole to raise a net, dump the crawfish(es) into the cooler, have a drink of beer, reset the net, and move onto the next net. Repeat continuously, net by net, until cooler is filled, or you've run out of beer.

Get the seasonings, a large pot, and a propane burner, more beer, and start cooking.

We catch crabs on a string tied to a chicken part. Raise the string and if there is a crab hanging on, put a dip net under it, then raise the crab above the water and hold it until it lets go and falls into the large dip net. Don't forget the beer. Repeat until you have enough crabs for the meal you want. We usely set out 1-2 dozen strings from a dock.