I don't get good results at weekends as people seem to be out, better this time of year get out in the evenings now as it's still light till 8.30 ish. I don't like knocking in the dark (winter) as much because I worry that people are concerned opening the door to someone and wary of my sales pitch when there's a stranger on the doorstep in the pitch black.
You'll find quite a few area's are already happy with/have a window cleaner and in these roads you'd just pick up a few stragglers, but every now and then you'll hit an area/road where they've had a crap cleaner or he's disappeared, then you can gain a customer almost every house !
In 2 or 3 hours evening canvassing I normally average 5 to 10 new customers. sometimes more if you get a needy area, and sometimes less, quite a few times 0 new customers !
I'd defo agree on the comment to price properly as much as you are able to from the start, better to grow slower and have the right customers/pricing.
Conquering the fear - 99% of people that answer the door open it looking sour and defensive, but once they realise you're just asking if they have a reliable window cleaner at the moment then they relax and are friendly, knowing they aren't going to have to get rid of a pushy salesperson, many will even apologise that they couldn't give you the business !
Don't forget to canvass commercial work too like small shops if you're trad only.