Yes , well done for starting out in the winter months, it makes a nice change!
Arm yourself with some leaflets and a clipboard ( even print some yourself if you cant afford,)
Present yourself casual but smart at the door, and politely enquire if they have a window cleaner, if they say yes.. say thanks for your time and move on...
Trying to undercut the customers current window cleaner is not a good idea, as you have to work out there,... and you are making a rod for your own back.
Dont price yourself cheaply to get the work, as you will end up with a poorly paid round and be a very busy fool.
And remember , you have to sift through all the "No thanks ".... to get a yes.
It can get you down unless you have staying power , and a will to succeed.
But once the ball starts rolling for you , you will see all your hard work pay off.