Spread Your name on the internet! Post you works on online Portfolio sites like Coroflot.com or
Behance etc.
I have to date received 5-6 request from
coroflot.com itself (some were ridiculous)! Obviously your own site will help too. Make sure your search engine optimization is correctly done.
A nice Visual identity and like amilelka said make sure your keep giving your business card to people. Make sure the Business card is quirky or something which is unique! People tend to remember that way!
You could also
'Stumble' your site or even
digg it!