It's been many a year since I went canvassing, but as others have said it's all about confidence.
Knock!knock!"Hi, good evening, I'm Dave Hutton the window cleaner,"
I look into their eyes long enough for them to look into mine, it's no good looking down shuffling your feet. Eye contact is important, you will almost always be judged by the look in your eye.
Using the words " the window cleaner" implies that you are well known in the area even if your not, and that's what you are, a window cleaner.
"We are expanding our round in this area and would be happy to give you a quote"[ eye contact point]
Note the we, actually it's the royal we, and it implies that your part of something bigger, not a wanaby one man band window cleaner.
Never ask if they already have a window cleaner, if they have and are happy with him, they will tell you soon enough. This is a business your embarking on, no room for sentiment, this code of honour amongst widow cleaner thing is with few exceptions total myth.
"How much do you charge? Do you mind if I look round the back to see how many windows you have? [ eye contact point] No go ahead."
At this point the old adrenaline starts to kick in. Walk around calmly whilst you work out the price. All kinds of doubt is fighting to get into your brain, kick it out, it's your worst enemy right now. Price according to your formula, and stick with it. believe me it's just so easy to think £15 and £12. 50 comes out of your mouth at the vital moment.
"Would you want them doing regularly on a four weekly basis? Yes
"Well, in that case you have nice windows with good access, I can do them for £15.00. [ eye contact point] Fine when can you come".
By telling them that they have nice windows with easy access, and that you can do them for that price, makes the customer think they are getting a bargain, or at least think they would have to pay more if they didn't have nice windows and access.
Once the first one is in the bag it gets easier, you can now name drop in your opening Gambit.
"Hi, good evening I'm Dave Hutton the window cleaner. Mrs Phillips from number 10 has asked me to clean her windows, and as I am now working this area could I interest you in a quotation"?.
People are like sheep, where one goes others tend to follow.
And above all remember, YOU NEVER FAIL UNTIL YOU QUIT