Walking around and loving it
The single most important thing that any of us can do as much as possible is to be thankful. So many people are lucky enough to live in a free country, where they can speak their mind, pursue the type of work they want to do (regardless of whether that is something that is your passion or something you enjoy doing to make money), date the people they want to date, be with the people they want to be with and also regularly forget how lucky they are to actually do that. Seems to be that in this day and age, it is much easier to just complain and look at what you don't have, what you wish you had more of, at the career that you definitely can't get because you made some wrong moves, and so many other things. Yet, it is so easy to recognize all the greatness of what we have right now, no matter which "right now" we are considering.
Don't forget to train yourself to be thankful for everything you have, and will have, and did have. Get into it so much that it becomes a habit. It's hard to make it a habit so you really have to force it at first until it is not only "second nature" but actually just your nature.