my friend paints (hes more of a drunk, laid back, smoke weed and paint wierd shit kind person)and hes sold a few pieces for some good $$$. hes tryin to open up his own shop, but thats gonna be a huge failure
i do websites for money, which is probably the most profitable for me at the moment. If you are working by yourself, and are a student, you are charging much much less than any graphic designer studio/company, however its still quite a large amount. I have been making sacrifices and charging way too low for stuff i do, but every time you do somehgin, it adds to your portfolio and therefore affects your relationships with the clients later on.
logos, cd covers, etc is something i've been asked to do lately, but its just some extra cash, not really that mmuch money.
im selling t-shirts now. Not that much profit either, unfortunately, but hopefully will bring me a bunch in a long run.
i know a bunch of people who sell their paintings and art, but since im pretty bad at it, i havent done it.