It's not easy to be happy all the time. Sometimes life gets in the way.

The good news is there are plenty of things you can do to boost your mood and put a smile on your face. In honor of International Day of Happiness — or any day when you just need a boost — try one of these ways to put your mind in a more pleasant place. They'll help you out when you're feeling less than chipper.

1. Go outside. Take a stroll around your neighborhood or, better yet, go walk in the woods. Studies have shown that walking among trees makes us relaxed, nicer people. Even just smelling the trees eases anxiety. The more green space in a neighborhood, the happier people say they are.

2. Exercise. Most of us spend way too much time sitting around. That's bad for our bodies, but also not so great for our mental health. Exercise modulates brain chemicals known as neurotransmitters. That includes dopamine, which regulates feelings of pleasure, as well as norepinephrine, which can help deal with stress. So find something you like to do and get moving.

3. Sleep more. When's the last time you had a refreshing night of sleep? It's common sense, but people who sleep well feel better. And when you feel good, you're happier. A poll of more than 7,000 American adults found that those who reported getting more sleep had an overall better feeling of well-being than those who got less shut-eye. The National Sleep Foundation recommends getting a minimum of seven hours of sleep each night.

4. Smile. It might seem hard to fake a smile when you don't mean it, but give it a try. Several studies have found that when people are in stressful situations or feel unhappy, if they force a smile, some of that tension melts away. Even a fake smile can make you feel a little happier, science says.

volunteers cleaning area in park When you think of people other than yourself, everybody benefits. (Photo: Syda Productions/Shutterstock)

5. Help people. Generous people typically lead happier lives than people who do things that only benefit themselves. A 2017 study found that generosity makes people happier, even if they're only a little bit generous. So go volunteer, donate or think about someone other than yourself. Everybody wins.

6. Care less about work. Don't let your boss in on this one, but try not to take your work home with you. Stop answering emails on weekends and don't do your presentation homework in the evening. Don't eat lunch at your desk; go for a walk and get away from your cubicle. Carve out some "me" time so you can destress and not let work consume your life 24/7.

7. Spend time with your dog or cat. There are so many studies that show how pets make us healthier and happier. They lower stress, ease anxiety, and enhance our physical and emotional health. How can you not be happy when your furry best friend greets you with a waggy tail or a purr each time you walk into the room?

8. Put your phone away. In a 2017 study, 300 people were told to go have dinner with family and friends and then randomly assigned to either keep their phones out at the table or to tuck their phones out of sight. When phones were present, people felt more distracted and they were less able to enjoy the enjoyment of face-to-face interactions.

9. Find a way to laugh. When you're just not in a good mood, try putting on a funny movie or getting on the phone with a silly friend. Laughter is contagious and will likely make you giggle.

woman meditating Meditation has all sorts of physical and mental health benefits. (Photo: Evgeny Atamanenko/Shutterstock)

10. Meditate. Not in the mood to guffaw? Then try some more inner-focused therapy. Many studies have found physical and mental health benefits of meditation, including stress relief and overall feelings of greater well-being. Whether it's taking a few minutes for some mindfulness in the morning or a serious mediation session, see if there's a meditation style that works for you.

11. Find some religion. Many studies have found that people who are religious tend to be happier than those who are not. A more specific study found that the religious are happier during times when societies are under stress. If peace is the norm, then people are happier whether or not they participate in religion.

12. Be grateful. Keep a gratitude journal. Write thank you notes. Mentally count your blessings. Appreciating what you have can make you happier and more pleased with life.

13. Have a good cry. Researchers from the University of Tilburg in the Netherlands brought together dozens of people to watch a couple of tearjerker movies. About half cried and half didn't at the end of the films. When they were asked to rate their moods once the movies were over, the noncriers said they felt the same before and after. The criers were sad immediately after, but then about 90 minutes later, they were much happier. Pass the tissues.

14. Forgive. Holding grudges can harm physical and mental health. When you forgive, you let go of the feelings that lead to bitterness and resentment. The alternative is reliving a transgression, which leads to chronic stress. "Rumination is the mental health bad boy," clinical psychologist Everett Worthington tells WebMD. "It's associated with almost everything bad in the mental health field — obsessive-compulsive disorder, depression, anxiety — probably hives, too."

15. Imagine being happy. Sometimes even being happy takes practice. Take some time to think about the people, places, smells and sounds that surround you when you're happy. How would you feel and who would be around?

16. Listen to happy music. There's a reason no one can frown (or sit still) when listening to Pharrell Williiams' song "Happy." It's infectious, upbeat and joyful. Listen to that and just try to be cranky.

17. Buy happiness. Forget the old adage. Money can buy happiness, but you may want to splurge on experiences instead of things. Cars, TVs and gadgets make us happy in the short term, but the novelty wears off. When we go on amazing adventures, we have memories that last a lifetime.

18. Make your bed. It only takes a minute, but making your bed is surprisingly satisfying. In a survey of 68,000 people by Hunch.com, 71 percent of bed-makers consider themselves to be happy people while 62 percent of non-bed-makers say they’re unhappy. "When I’ve asked people what happiness-project resolution has made a big difference in their happiness, many people cite the modest 'Make your bed,'" writes Gretchen Rubin, author of the bestselling book "The Happiness Project.”

19. Declutter. Clean your closets, your drawer, your DVR playlist. Getting rid of things you don't need that are just piling up can help make you more productive and much happier.

20. Hang out with happy people. When you're with cranky people, it rubs off on you. So find some positive people and let their optimism be contagious.

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.