1. Spray hairspray into the aluminum drink can.
2. Stick the lighter into the can and press the trigger on the lighter.
3. This will ignite the hairspray mixture and launch the can in the air.
Lighter/smaller cans will fly farther.
Try to light the hairspray mixture on fire as soon as possible after you spray it into the can, because the hairspray will be more atomized and you have a better chance of making the hairspray explode.
Try experimenting with other kinds of hairsprays, deodorants, alcohols, etc. Each will yield different results.
Try to hit a target.