1. Always accelerate slowly if you're stuck in the snow; spinning the wheels will only dig the car in deeper.
2. Make sure your tires are pointed straight.
3. Turn off traction control as any slipping will cut off power to the wheels.
4. If your car has a manual transmission, you can try to rock the car back and forth by quickly shifting from the first/second gear into reverse and back to first/second gear again. Doing this may just give you enough momentum to pull yourself out.
5. When driving in deep snow, try to keep the car moving (if it is safe to do so) and only come to a full stop when necessary. It is harder to get the car moving when fully stopped in deep snow than when you are already moving, even when it's just a little bit.
6. When you're completely stuck, sometimes using your floor mats under the tires may help you get out, but remember to accelerate out slowly.
7. If you have a rear wheel drive vehicle, consider buying a couple sand bags and putting them in your trunk. Having additional weight in the back will give you more traction in the rear.
8. If you have a snow shovel, try to dig yourself out. You may need to dig out all wheels, and worst case scenario, underneath if your car is sitting completely on snow.
9. You can try letting some air out of the tires, but don't forget to re-inflate them as soon as possible. Also, if you have all-season tires, think about investing in winter tires - good winter tires make a big difference.
10. If all else fails, you can call a tow truck to pull you out.