Good for you m8. As for canvassing, just be friendly and considerate in your attitude, dress tidily without being too formal, polite and generally happy in your demeanour and you'll be fine. You inquire wether they want a window cleaner, I do the frames as well as the glass, would you like a quote?
Answer = Yay or nay, thank you and good night.
The more you canvas the more customers you will find. Good hunting.