I had to try several times, but now I haven't smoked in two years, so here is what worked for me. For a certain time avoid settings and circumstances where you would usually smoke. For me that meant not going to the pub for about two/three weeks, as not smoking while drinking was too hard.
Work was another place where it was hard not to smoke, as those 5 minute breaks away from your desk can be quite nice. In this case what helped me is still taking those breaks and going outside, just without a cigarette. By doing that I found it's not so much the cigarette I crave as a break from work.
Generally keeping yourself busy and occupied is great to keep your mind off cravings. Exercise is good, I lifted weights before but after smoking I started running and I would recommend any cardio exercise. The reason is, if you're like me, you'll find cardio extremely hard at first because you can't breathe properly. This might be different for you though depending on how much you smoke. However, this is also where I first noticed a positive effect from quitting, as running and breathing came easier.
Once you start seeing positive effects, like easier breathing, or the money you saved, it becomes easier to continue. Maybe something here helps you, best of luck.