As a newbie, BUT being experienced in another similar business (car valeting/detailing) I'm used to these type of customers too. It's even worse when you have 5 x £30 mini valets booked or even worse 2 x £75 full valets and the customer only tells you when you turn up "ohh, sorry I need to go out, I'll call you and re-book ! " these are dumped straight away.
This past experience has given me a head start I feel when it comes to building my round and dealing with the issues discussed. I know the value of not undervalueing and taking on PITA customers just to get work, but then realise the work isn't worth it and a pain and waste of time.
So I'd say to anyone reading who is new to being self employed in window cleaning, don't undervalue yourself and under quote or put up with PITA customers JUST to fill your diary, better to build more slower if need be, and price what you think is a good earning
from the start. It'll be a lot better for you in the long term.
So to any newbies like me reading, take something from the posts above and don't put up with excuses that are not deserving of the cancellation from the start, and leave that space in your diary free for a better customer, they will come along soon, hopefully