It can be easy to pick up side gigs building brochure ware websites for companies. Just approach a business that doesn't have a website that should (coffee shop, CPA, doctor, etc, etc) and tell them you can build them one. You'll need to be persistent, though.

If you are ambitious, you can turn those into recurring revenue by reselling hosting--I haven't done that because I don't want to be on the hook for down websites.

Make sure you check with your employer and get written confirmation that this is OK.