Hi Steve
It's been a long day so I havent been able to have a good luck at your website. The main thing I noticed is you've only inputted keywords for your home page - by adding keywords to each page (relevant to that page) it gives users more chance to be linked with your site. For instance if you've got two pages 1 with 1 set of keywords and the other with a totaly different set then theres two pages listed with different ways of finding it. Another good thing is dont be afraid to add additional pages (one for commercial work, one for domestic work, one for carpet cleaning etc) this way on the domestic page you can add keywords directly associated with that, on the commercial it can be keywords directed towards businesses - you get the drift.
Just a quick word about keywords. The way 95% of search engines link you is by a percentage factor. If soeone types "window" and "cleaner" it will search for sites with these two words in the most times, if however person A has just got a site that says window cleaner and nothing else and his keyword says window cleaner with nothing else he has effectively got 100% match with the search. If person B has window cleaner in his keywords and on his site along with "joe" and "bloggs" he only has a 50% match - this has a big bearing too - person A will be above him.
The key is to be selective use the words that people would think of if they wanted your services but don't put too much.
Another thing to do is always make it plural. If you have windows instead of window as a keyword people who type window or windows will still match with you - were as if your keyword isnt plural and youve just got window then if someone searches for windows they will not match. If that makes sense.
I always add a description meta tag too as it gives certain words even more exposure.
Always make your page names relevant as these add for additional words when someone searches and even your site name - thats why ive got the long winded centralwindowcleaners - because it helps give more exposure to the words window and cleaners.
I'd try to add place names to your keywords as well - such as - I clean mainly Redditch and Bromsgrove so Ive listed these to names as well as surrounding areas names as well as all the districts - so if someone searches for a window cleaner in theire district of say Redditch and its an area I cover Ill be 1st in the list.
Hope this helps a bit.