’Tis the season to celebrate – and also the season to feel overwhelmed, lonely, angry, irritated, and rushed.

Here are nine tips for keeping yourself feeling happy during the holiday period.

1. Get enough sleep. Turns out that, although it seems like a minor life issue, not getting enough sleep is a major disturber of people’s moods. Jet lag, traveling, parties, and over-excited children all make it hard to get your usual number of hours. Making an effort to get to bed at a decent hour really pays off.

2. Exercise. Studies show that one of the quickest and surest ways to boost your mood is to exercise. If you’re away from home and can’t do your usual routine, even a short walk will help. Even better…

3. Go outside to exercise. Or at least go outside. Light deprivation is one reason that people feel tired. Research suggests that light stimulates brain chemicals that improve mood and focus. For an extra boost, get your sunlight first thing in the morning

4. Stay in control of your eating. It seems to me that guilt about holiday binging is a major source of the blues. It’s easier for me to abstain than to be temperate. It seems Scrooge-ish not to have gingerbread cookies or bites of a Winstead’s Frosty, but I think I would be happier if I weren’t worrying about it.

5. Don’t rush around. Hurrying to pack, rushing through stores, sprinting to make a flight – these are sure to put you in a bad mood. Give yourself plenty of time. Do a few errands or buy a few presents each day. I get out a suitcase a week before we leave for Kansas City, and I toss items in as soon as I think of them.

6. Learn from the past. What has made you unhappy in years of old? Think back. Avoid your triggers. Stay out of the kitchen, stay out of the mall, stay away from Uncle Billy – sometimes there’s a weird triumphant satisfaction in getting worked up, yet again, by a particular situation. Don’t do it! Don’t expose yourself to known happiness risks.

7. Make time for real fun. Sometimes holiday vacations, which are supposed to be “fun,” are actually just a huge hassle. Figure out ways to have fun. In my family, we decided to reduce gift-giving. All the adults “draw” for each other’s names, and we each buy stocking presents for just one other person. Also, include time for things YOU like to do: going to a movie, taking a nap while everyone else goes skating, going to the gym.

8. Behave yourself! If you sulk, snap, tease, or shirk, you’re not going to feel happy. It may feel good, but only for a moment. Then you’re going to feel bad. Instead, try to help out, bite your tongue, clean up, or run to the store. Look for opportunities to say, “Don’t worry, I’ll take care of it,” or “This is fine,” or “What should I be doing?” Do good, feel good—this really works! The way we feel reflects the way we act, so if you act in an affectionate way, you’ll feel more affectionate.

9. Fill your heart with love. Remember the Twelfth Commandment: “There is only love.” If you’re heading into a difficult situation, take a moment to fill your heart with love. Think of all the reasons that you’re grateful to your family, and the happy memories you’ve shared, and how things might look from other people’s perspectives. This can be very hard to do, but it will make you happier. And if you’re happy, you’re going to be better able to make other people happy. That is the mystery of the Second Splendid Truth.

Remember, holidays are supposed to be a time of peace, love, and fun — and we can’t bicker, complain, and nag our way there. Figure out what YOU need to do to keep a holiday spirit.

Gretchen Rubin is the author of the #1 New York Times Bestseller The Happiness Project—an account of the year she spent test-driving the wisdom of the ages, current scientific studies, and lessons from popular culture about how to be happier—and the recently released Happier at Home and Better Than Before. On her popular blog, The Happiness Project, she reports on her daily adventures in the pursuit of happiness. For more doses of happiness and other happenings, follow Gretchen on Facebook and Twitter.

Image courtesy of Tim Gouw.