Even if you do not feel like working on any of your past hobbies, you may find that those activities that once brought you pleasure can be satisfying to do again. If you used to read novels, consider joining a book club. You will get to read a new book and socialize with others, these bring even more benefits to fighting depression.
If you used to whip up a pair of knit socks every week, visit your local yarn shop, select a beautiful hank of yarn, wind it into a cake and get your needles clicking. The tangible aspects of a hobby and creating a finished product can remind you of the skills and talents that you have.