I used my own pictures. So hope you enjoy. Tons of people know how to do this, even if you don't know, it's basically common sense. You just ignite something flammable. Sorry about the knife, used it to take wrapping off the lighter.
1) Get a can of body spray. (Axe, Tag, etc.) Don't waste your money on it. I used Adidas since it was cheap, got it for $1.99.

2) Next just buy a lighter. Regular Bic lighter works fine. I bought mine at a Flea market for $.50
3) Just hold down the nozzle of the can and then once you have a steady flow put the lighter up to the stream.
4) You'll get a flame, about a foot in length. Just be careful and don't burn your finger....Other than that it is pretty safe.
And your finished result!
Edit: Errmmm sorry about the big pictures.