Add your website address to EVERYTHING. Your email signature, letterhead, invoices, business cards, giveaway items, forum signatures, Facebook profile (and all social media), voicemail message… anywhere you can think of.
Create a listing on Google Places. All you have to do is answer some simple questions about you and your business and upload some photos. Google will send you a postcard a few weeks later to verify your address.
Submit your website to online directories. There are lots of free directories, and plenty of paid ones. The cost benefit is your call. But make sure the directories you submit to are appropriate to your business, otherwise you’re wasting your time.
Answer questions and post relevant information on forums your target audience frequents.
Send follow-up emails to your past clients. Be sure not to SPAM them, but keep them aware that you’re still in business and ready to serve them again.
Start an email newsletter. There are services like ConstantContact and CoolerEmail that do all of the hard stuff for you. If you don’t have design skill, you can just pick a template and start writing! They even handle all of the opt-outs, so you know you’ll stay legal.