Educate yourself about what smoking does to your body. Imagine it on every inhale. Make yourself really hate it. Set a specific end date in the near future (but keep it to yourself, you don’t need outside pressure). In the meantime continue thinking about how much you hate smoking. Then stop cold turkey.

If you miss smoke breaks with others at work or whatever, just keep hanging out with them but don’t smoke. If they ask about it, don’t say you are trying to stop, say you did stop.