Sometimes it helps to remind yourself that you're not having that (whatever you're craving) right now, but maybe tomorrow/next week/next month, if you still want it. Then distract yourself with either a healthy, low-carb treat or by doing something else entirely.

For me some of these cravings are just routines, like being used to having a dessert or snack while watching TV in the evening. If it's late enough I might just go to bed. Earlier in the evening, I might break up the routine and habit by hopping in the shower. By the time I'm done with that and gone back to watching TV, my body has switched gears (and I've just bought myself a bit of extra time for the next morning). Or I might spend some time doing some chores you need to catch up on--20 minutes worth of filing from that pile of paper and another 10 or 15 running the duster around the shelves. Again, it gets my body to switch gears from the usual routine.