Dress smart casual. Logo'd sweatshirt or tie and collared shirt. Clipboard in hand.
Walk in and say:
"Excuse me; I run the local window cleaning business in ___________(name town or suburb) and we clean for folk like (name two well known local businesses that you do work for) and we are expanding into this area; who do I write to to offer our services?"
If name given then write it down and ask for the address or a compliment slip. Then say:
"While I'm here may I take some details of your premesis so that I can provide a quote to Mr. XXXXX?"
Jot down layout of windows and walk away.
Then write/email in and follow up with a phone call.
Possible responses:-
1. Gotta windy/don't want one
2. You can talk to me (Receptionist/Queen Bee/Secretary)
3. You get given details.
4. You need to contact head office
If you get option 2 then walk round, talk about frequency and scope etc and write down figures a bit higher than you would do it for say "thats what it comes out at" and show it to the person and gauge their reaction.
If they go "ooh err" then say "well, you'll look a bit more closely and see if you can shave it a bit or do it out of normal hours and fit it in with other nearby work and ask whether that might "swing it".
Be flexible -
Some small units will pay cash (Up to say £25) out of the petty cash for a receipt others will pay by cheque on the spot (£15 - £35 plus) and others insist on an invoice and 30 days (£30/£40 plus).