I used to do a bit of canvassing, but find I don't need to now, but there is some advice I,d like to give that I found very useful. Pick a small area at a time and concentrate on that. I never drop flyers, it's a waste of paper, always call personnally on people (let them see that you are an honest and reliable window cleaner). When someone answers the door tell them that you have been asked by to clean the windows of a house in the area, and that if you could get some more customers (to make it viable) you would do them. this makes it sound like you are already there, and may pursuade them. You can give quotes, saying that if you do get enough people, you'll take them on. If you don't, or don't want to proceed with them, you can call back and say that you didn't get enough so won't be doing it, this way you won't loose face if ever you go back to that area again, and at this point give them a flyer.