The thing here is to find something you really enjoy no matter what mood you're in so when you are depressed this activity is even more important to you. It doesn't have to be extravagant or expensive, but just something you really like to do. Everyone is different so whats good for someone else may not be good for you.
It really has to be special to you and it can be anything and the best part is that no one else needs to know about it, so do a little thinking outside your comfort box and you'll come up with something soon and then you've found your key to your own little bit of Paradise. Good luck