Of course! There's a lot of things you can do.
1) Self-help. There are a lot of self-help books out there now. One of the best is Feeling Good by Dr. David Burns. It was written a while back, but it's still the best when it comes to cognitive behavioral strategies to assist in recovering from depression. Here's a link: http://www.amazon.com/Feeling-Good-New-Mood-Therapy/dp/0380810336 There are tons of exercises and self-guided tools to help you keep your thoughts on track.
2) Anything that increases your endorphins - like mild/moderate exercise or laughter (I guess it really is the best medicine)!
3) Setting small, achievable goals for yourself and following through. Depression has a way of paralyzing people. Setting small goals everyday and pushing yourself to accomplish them will help you to stay active and in the mix. For example, set a goal of going out to lunch with a friend once this week. You may not feel like it, but once you get out and do it, you may feel differently.
4) Speaking of friends...engage social support. Social connection is a good way of helping us to get out of the dumps. Try to stay connected to friends, family, and other positive influences when you're feeling low.
5) Help something that needs your attention more than you do. Volunteering at an animal shelter or walking a neighbor's dog can really help if you don't already have pets. It will get you out of your head and focusing on something else that is a natural upper.
6) Eat well - foods high in omega-3 fatty acids (or even taking fish oil pills) can help boost your mood.
7) Cultivate a hobby. If you don't already have a hobby that you engage in, find something that has always interested you and try it out. One of the number 1 reasons that people suffer mild depression is because they feel "ineffective" or like they are wasting time (just watching tv, etc). Finding something that occupies time that you enjoy and feel good about is important. And, it's basically what successful retirement is all about when you get to that stage of your life!
8) If none of the previous 7 tips work for you over time, realize that you may need to seek further help. Getting checked out medically for any physical contributors or going to a counselor for therapy/meds might be the right thing to do at that point.
I wish you the best and if you have more queries, feel free to ask.