Further to the above posts - especially Maggie 67 - After you've sent the intro letter - about three working days later phone recipient and try to make an appointment to explain your services.
Put yourself in their position - what's the easiest thing to get rid of? A letter! The next easiest? A phone call. The hardest - a body - yours when you are sat in their office professionally explaining why you are the best thing in window cleaning sinced sliced bread.
So if you seriously want this kind of work you've got to send a letter, follow up with a phone call and try to get to see the person.
Break out your wedding suit, take in the flares (or let out the drainpipes) let out the waistband, throw away the waistcoat (remember them?) (unkess you're texas girl in which case it appears she is getting younger and trimmer every year!
) clean your teeth and smile winningly (like chartermarque's avatar).
Bob's your mother's brother go to it!