If this is a situation of more feeling down that you are calling depression versus actually being clinically depressed, I would suggest this: do something for someone else.
I know it sounds crazy, but it actually works. It doesn't have to be something big, it just has to be something for someone else. For example, I was going through some things a few years ago at my job. When I was really feeling low, I went out to lunch and brought back slices of cheesecake for various co-workers.
The look of surprise and gratitude on their faces when I gave them a slice actually made me smile for the moment. Sometimes, you just need to chip away at the things that are getting you down, just as the things that are getting you down stack on top of each other.