The more doors you knock, the closer you will get to achieving your goal. There is a canvaser on here (GD) who I believe knocks between 2 and 8, with a break at around 3-3:30 to allow for mums doing the school run. He does really well, and will probably see this thread and give you some sound advice.
All will agree it's a numbers game. If you get a lot of people saying there's already a window cleaner in the area, don't be put off. There are still plenty of people looking and having difficulty finding a good windy. Finally, there's no such thing as a patch, so again, don't be put off if you meet someone who tells you otherwise.
Best wishes,
John