I agree. When I first statrted cleaning, I deliberately kept my rate low. This allowed me to learn on the job and gradually get new customers. After 2 years I began to raise my rate, and I became a whole lot more picky about taking on new customers.
I think its crucial that you find your own niche. I did, and it has helped tremendously. Think about what you love, what you like to do, and see if there is a way to incorporate those things in your marketing. For me, it was my love of animals, especially cats. MMost pet owners want to hire people who are very comfortable around animals and who wont be bothered by "pet messes." I am one of those people. Currently, 75% of my customers have cats, and they have me not only clean, but also do cat sitting when they go away.