Hi Andy
If i wasnt such a busy feller, i would come over and show you myself how to generate work as i only live half hour by train from you ( Leafy Suberb Called Hertfordshire) I was talking to an old friend today who is a site agent in central london, He informed me that there is massive demand for Shiners up there Especially offices but if you want to go that route you should join the National federation of master window & General cleaners find them at
http://www.nfmwgc.com/ as you can then use the logo on your letterheads and get specially nagotiated rates on required insurences etc and it looks more proffessional when submitting quotes etc........but make sure you do some enquiring first with companies so you can find out who it is that you need to approach with regards to cleaning contracts etc normally a quick phone call to a receptionist will get you this information if its just houses you want to clean which i think is the case then i am affraid its on the knocker or a leaflet drop, followed up by a door knock etc...........Hope this helps and Best of luck with it.