There are a few ways to get customers. Building a reputation so they will come to you is great, but not very reliable.
So assitionally, you should make a list of potential customers (start with the yellow pages). Do a little background research on them (Google is your friend), and have a look at their current website. See what their site is doing and where it could be improved. Then write a short proposal of what you would make differently. (Use their vocabulary, the business guys don't say 'functionality', they say 'value added'...) They all have a website. You need to explaion to them why they should spend money on getting a better one.
After you have prepared yourself, ring them up. Sound really businesslike. Do not tell them your life story, and that you are just starting out, or offer them anything for free. (In many peoples mind, there is still the association for free = crap.) Instead, tell them that you have an offer for them. You noticed that their website still does not support feature XYZ...
Two things are important in such a phone call:
Be brief an concise. They are important businessmen (well, at least they think so), so don't waste their time.
Do not let it affect you if they are not interested. There will be many of those. You need to call maybe 100 people in order to find one that is a potential customer. Or maybe 200. It sucks. You still have to go through with it.
I also remember someone telling me that he bought his current website at an ebay auction for €20. This is certainly a way to assemble a small portfolio of projects. It does not pay many bills, but it can be a start. Still, the hard work of researching and calling potential customers is still the most important part.
I hatetd it, that's why I took a job in a big company.