This is the kind of quick DIY that will help you survive in the woods or, say, after the zombie apocalypse.
You'll need the top tab off a soda can, a metal nail file, and a cutting implement that can cut through flimsy metal (any scissors or wire cutters would work here).
Step 1: Cut a small strip of metal out of the bottom (larger) hole in the can tab. Work at an angle, so the remaining edge is very sharp and hook-shaped.
Step 2: File the "hook" part of the can tab to a sharp point using the nail file. You could probably go caveman and use a rock for this task in a pinch.
Step 3: Tie your fishing line (dental floss, skinny rope, whatever) through the intact hole -- the top, smaller one -- of the tab.
Step 4: Bait your hook and out-fish your less resourceful peers.