Shop early in the day and early in the week. If you can, shop before the holiday season gets into full swing. That will reduce the likelihood you'll just buy and bolt to avoid the holiday press. Hasty shopping often causes you to overspend. If the season is starting to get to you, take a break.
Stress leads people to make purchases under pressure and overspend.
Before you buy a gift, make sure it fits your price range as well as the person you are buying it for. Avoid impulse buying. Before you go out, know which gifts you plan to buy and take enough cash for those purchases. Using cash forces you to stick to preset spending limits. Credit cards can make holiday shopping easier in the short term, but will burn you in the long run.