You can definitely do this, but you need to be smart about it and assess how much time you realistically have. If you do have, 10-15hrs a week - this could be great. I won't comment if you actually will have this time - that's your call! But assuming you want to:
How I'd do it:
- If you don't have a great website with your work / skills - MAKE ONE NOW! Also, get some business cards - as cliche / outdated that is - it makes the old men think you're serious - along with good work on your site.
- Go on StartupDigest, Meetup, Craigslist, OHours, etc. and find the local networking events for web design, tech, startups and small business - then attend all of them that look promising.
- You won't have the time to drum up a ton of business on your own, but you can show your site to the people you meet who are already serving the same customers - here are the targets:
+ Other Freelance Web Designers / Programmers / etc.
+ Tech "connectors" - who shows up at all these meet ups and know everyone? - find them
+ Consultants / Business Service People - these people often provide ancillary services like translation, HR, etc., but they're always looking for more services they can provide their clients. They are often snakes, but when they get a client interested - it's still money. Just filter appropriately.
Impress the good people you meet & keep up-to-date - you'll get some pretty easy deal flow - programmers are in high demand everywhere & you can afford to be selective & charge market / premium pricing.
INAL and not sure on your background, but you should probably set up a simple S-Corp / LLC and have a simple contract - even steal another service providers - you want shit on paper to keep in clean & filter the shit clients.
Hope that helps.