Buy the cheapest soldering iron you can find. Drill a big enough hole at the bottom of the can to fit the iron in. Burn out the can. Soldering iron into the hole, fill with wood chips. Cover the can with foil, poke some holes in the foil. Plug in the iron.
Also A-Maze-N Pellet Smoker. Pellets are much more readily available and burn longer because they are compressed. A full maze will burn almost 11 hours if needed.
Quick & simple, I've been using this for a few years now:
Tin can, open with a can opener 1/2-2/3 around. Empty, clean, & remove wrapper.
Use a church key to punch a hole in the other end.
Fill can with wood chips from the end opened with the can opener, push an unused soldering iron through the hole made by the church key. Start smoking.