Using Craigslist yet? Here's how I set up my ad (several times per week):
Go to www.boston.craigslist.org
Find the "services" column. Click on "household".
In the "search for" box at the top left,
type in any one of several keywords: "natural carpet cleaning", environmentally, eco, organic, nontoxic,
green, etc, and one or more of my recent ads should appear.

Where in my ad copy I cite various awards, citations, mentions in local media, etc., you could substitute 2 or 3 testimonials from customers you have pleased to date. Make sure you ask them if they will allow you to paraphrase any nice things they may have said about the results of your work. You'll note near the bottom of my ad I include a list of several keywords that are not in the actual text. The Craigslist search tool will find these when someone does a search. People search using various terms, all of which mean more or less the same things. It's awkward to try and force all of these into good ad copy, and listing them at the end accomplishes the same thing.

Opps, forgot. ON the Craigslist home page you'll find a list of states and cities where Craigslist has service. If you don't see you main city or metro area, click your state, and there you will find a list of cities, and groups of cities close by to each other. Hopefully you will be located close enough to one of these so that your ad will be effective. Craigslist is also open to suggestion to add new locations.

The more frequently you run your ad, the more people will subconsciously respond to it.