Try to win a few projects on https://www.elance.com or other freelance sites. Bid only the minimum price if the project isn't too large (until you get more experience and projects under your belt on the site).
There's also http://fiverr.com, and you can sell almost any type of service you can think about for $5. Check the ones that already exist for inspiration.
There's also http://fiverr.com, and you can sell almost any type of service you can think about for $5. Check the ones that already exist for inspiration.