When you run out of weed, go out and buy some crack instead of weed. Haha, just kidding...

I think some of the suggestions on here won't work, and some of them might work to an extent. Lol, but to be honest, the only way you can truly do it is by will alone. Oh, and just think... if you don't smoke as much, you'll have more money to spend (maybe even for weed! Hahaha! Just kidding.).