Links from other sites to your site. Google sees that as good. If its a link from a link directory, it probably won't give much weight, as it knows anyone can submit. However, if it picked up a link from a good Window cleaning blog for instance it would flag it as decent and give you a bit of credit for it.
Keywords...if your site doesn't have "window cleaner dunmow" on it, then it's unlikely that you are going to rank for it anyway, you'll need even more links that you would with the phrase "window cleaner dunmow". Keyword density (the amount of times the keywords should be in the text) should be around 1-2%, so that means putting Window cleaner dunmow every 100 words (or so), that will help.
Not sure if that helps.