Little more info maybe? What is your target base, your location, years of experience...etc etc. What have you already done? It's hard to help if we don't know the basics. Unless you really have a unique specialized area, word of mouth will either increase or decrease your business based on previous work. I usually get at least a couple of referrals each job I do, and from there it spreads exponentially. Get at least a basic website complete with a portfolio and make up some business cards. Drop off the business cards w/ a link to your site at places where prospective clients would see your card. For instance, if you are into shooting maternity and baby and family portraits, drop off flyers at OB/GYN offices. Mail out flyers a year or so following a wedding shoot to the couple, etc, etc. Really though, word of mouth can be your best (or worst) advertisement.