I never gave them a letter, the ones I saw I spoke to whilst cleaning the windows and cleaned up the frames trad before hand.
I think giving a letter is asking them to get out there and check for faults that you will make. to much info to people can backfire.
My honest advice would not be to give a letter, this worked for me. It may be different for you, but I can only go on what I do and have done in the past.
Ian
Thanks Ian, I have been told not to give a letter before. You could be right they may just try to find fault,
I have known most my customers for a long time and as soon as you knock most want to pay thinking you have already been and cleaned the windows, so there must be some trust from them.
Do you think I should do it this way,-when I put my prices up next year of approx £1.00, I will state that frames will be cleaned aswell from now on
Darren