Start With a Good Dose of Gratitude: 
Your level of happiness can change simply by the acknowledgment of what you're thankful for. That is why in the morning, there is a common ritual to spend time recalling the things for which you feel grateful. Or, before you go to bed, keep a gratitude journal for yourself that day and write down 3 to 5 things that you felt grateful for that day and why.
Make Sure You’re Giving Back:
Did you know that giving 10% of your income to your favorite charity or organization makes you feel better and feel good about yourself because instead of spending money on yourself, you are giving to others. The Universe takes in this message that is being sent, stating that you know everything's going to be alright. By giving, you’ll be taken care of, too. You see it from those with very little to those who have millions: you have to give to get, and by doing that, your happiness increases.
Laugh Every Day:
Laughter strengthens your immune system, boosts mood, diminishes pain, and protects you from the damaging effects of stress. Nothing works faster or more dependably to bring your mind and body back into balance than a good laugh.
When you laugh, you release happy hormones called oxytocin and endorphins. These are hormones that uplift us as we share experiences with others. Even just making yourself smile will put you in a better place. Go ahead and give it a try. Turn the corners of your mouth up into a smile and then give a laugh, even if it feels a little forced. Once you've had your chuckle, take stock of how you're feeling.
Do What You Love:
Who doesn’t love a good hobby? Release the tension of your compressed negativity that is held up in your body and mind with your favorite physical activity — maybe it’s kickboxing, rollerblading, or karaoke. Or maybe even something a little more calming, such as, rhythmic activity like painting, knitting, or gardening.
References:
https://liveyourlegend.net/wake-up-call-doing-work-you-love-could-save-your-life/
https://www.lifehack.org/articles/communication/14-things-proven-make-you-happy.html
https://www.massgeneral.org/wellness/news/what-are-the-health-benefits-of-doing-what-you-love
https://thrive.kaiserpermanente.org/thrive-together/live-well/health-benefits-of-doing-what-you-love
