This is the best tip of all. Holidays are not for stress or for over-indulgence, but for responsible fun!
Preparing food carefully should always be a priority, but during the Holidays you may be cooking for a larger group. One important tip to remember is to keep all raw meat and fish away from anything else. Wash your hands repeatedly.
This is a simple one, but why during the Holiday season especially? You will most likely be around more people than usual, especially children. Do not let your unhealthy habit affect them. If you must, be courteous and make sure your second-hand smoke is not reaching anyone around you.