As a counterpoint to those newbies who find they are leaving spots; I did a first time clean on a house today..sorry...yesterday

This was a march out clean (local army camp) the house had all UPVC windows, they were completely minging too, also, the front window frames had all started to oxidise and the water was coming off milky.
I do several of these houses on regular cleans, they usually take between 10 and 15 minutes to do, this one took 25 minutes.
The windows on the shady side of the house I wasn't too worried about, but did have general concerns because they were so filthy.
The sunny side windows I was certainly concerned about, again, in part because they were so filthy and also because of the oxidised frames.
Shortly after finishing this house I met up with Squeaky and helped him cure his airlock problem, while chatting my wife rang me and said that she'd had a phone call from the house I'd just done to say that I'd left a couple of pole section behind

(I'm a shocker for this kind of thing

)
On picking up the poles I checked the work over....I couldn't fault it, back and front were fine.
Maybe if I walked around the inside of the house and checked every window really closely I might have found spots here and there, but on general inspection I could find nothing wrong.
Now the point I'm making is that experience counts for SOOOOOO much!!!
This wasn't just one of my existing houses that I cleaned all the time and therefore little more than a repeat clean, this was a stinker, very dirty, full of spiders nests and half the window frames were oxidised.
Yet on a first time clean I got them spot on (no pun intended).
I'm not trying to say that every house and every window you do will be perfect even with years of experience, but as you gain experience, even on first time cleans, the incidence of spotting will be greatly reduced.
So don't lose heart just because you cannot seem to get it right...stick at it and you will get there!!
Ian