Think of something else. Distract yourself from smoking. It's like if you're running out of steam on a hike, I get into an indepth conversation with someone, or if I'm on my own i think about something. Remind your body your mind is in control, not vice-versa. Above all good luck mate, quitting smoking is one of the best tihngs you can do. Set up a pot for money saved instead of buying fags, see how much you save. The financial incentives are there.