The goal when you use any fish trap is to catch fish. You want to make a fish trap that the fish can swim into but not out of. Part of the trick is the bait, but a big part of the success of any fish trap is its design. Here's a simple fish trap you can put in a river to catch a mess of fresh fish.
Cut a 3-by-5 foot section of wire. Form this into a cylinder that's about 2 feet wide and about 3 feet long. Use the 18-gauge wire to tie the edges together. Overlap them to make the trap sturdier.
Use the wire cutters to cut a circle of wire about 1½ inches bigger than the cylinder. Bend the wire around one end of the cylinder. Use the 18-gauge wire to connect the circle to the cylinder.
Bend a section of remaining wire into a funnel shape. The length should be about half of the cylinder. Leave the hole on the narrow end large enough for a fish to swim into. The wider end should be the width of the mouth of the cylinder. Use the 18-gauge wire to hold the funnel's shape.
Attach the funnel to the remaining open end of the fish trap. Secure it with 18-gauge wire.
Create a door in the side of the cylinder. Cut 3 sides of a mesh square. Make it big enough to get your hand into so you can bait the fish trap and remove your catch. Tie the door shut with a piece of wire.
Bait the trap with an old sock that's got some dry dog food in it. Tie the sock about 6 inches beyond the end of the funnel. The fish swim into the funnel in search of the good-smelling dog food bait. Once they enter the trap they can't figure out how to get back out.
Tie a line onto the trap. Toss the fish trap into the river. Wait a bit, and then pull it out.