The Habit of Gratitude is something that can be incorporated into your daily routine with practice. Maybe you can jot down three things that you're grateful for in your journal each day. Another idea is to intentionally and deliberately try to tell someone (even a stranger) of why you're thankful for something that they have done, even if they've just held the door open for you or let you pass in front of them in the grocery aisle.
When we have a grateful mindset, we tend to involve ourselves in other practices that improve our well-being, such as meditation, sports, and recognizing our strengths. Second, it moves us to be kinder, more thoughtful, and more altruistic. And third, research shows that gratitude, when expressed effectively, increases the probability of the recipient to lend favor to a third party (ie paying it forward).