If possible, start a little nest-egg for hobby use. I started my "Bullet Fund" by doing a little tutoring after school. Every now and then I'll sell something I don't need and the proceeds go in the BF. Now that I carry a cell phone all the time, I discovered that I had a bunch of useless wrist-watches that got sold. I toss my spare change at the end of the day into a jar and take that to the bank machine 2 or 3 times a year. Keep your eyes and ears open for a quick-turn investment. If you can buy something today and turn it around for $150 tomorrow, you've got another $50 in the BF.
It all adds up.