Do freelance. Go to sites like http://www.freelancer.com/
(or the equivalent for your country if you have one) and try get a gig there.
I was freelancing fairly frequently at one period of time, mostly as an English-to-Russian translator, netted me 200-300 dollars a month which was a LOT in my home country (plus I usually actually worked only on weekends and didn't take upon many projects)
2 things, though.
a) Freelance is not a secure job, your projects end, you need to find AND fight for new ones, especially if you're not known in the field (which is also the reason why you won't get big gigs until you get tons of exposure).
b) Be wary of who you work for. While I in my personal experience have never been scammed, it's the Internet. So try to see how professional the job posting looks, do the research on the person/company, NEVER accept work from people with free e-mail hosts like yahoo and gmail, and always protect your work (for example, if you do a piece of art, at least watermark it when sending the results so you wouldn't be scammed for money, and then send the actual piece when you're sure you'll get paid)
Also, I must say that I never actually used freelancer.com, I used other, east european, sites. But as far as I know it's like the biggest English freelance site. Search for some other ones too.