Exersize, read, work, get a hobby, rub one out, take a class, meditate, yoga, learn to cook.
Most of all, enjoy spending the money you're saving instead of spending it on dope, booze and cigs.
I have nothing against pot or alcohol, btw. Anything in moderation is cool. It's just that certain things don't lend themselves to moderation.
Congrats to you for quitting.