We use what we call "General optimization". It involves doing scored keyword research on a wide range of keyword phrases that relate well to the site. From this we strip out all the junk and have a good list that contains the most popular and most generic keywords, to the very low score, but highly targeted phrases.
We then optimize the site and try to use as many as possible while creating titles and descriptions that are well written to "sell" the content.
What we have found is that if you analize the list you will see how you can create phrases that will include 2,3, or more phrases within the copy. It's like a kind of word puzzle.
Here is a real (but simple) example:
web site hosting,69480
free web site hosting,30779
If you can use the last phrase because it relates to your site, you do not have to use the first two as much, because they are contained within the last one.
This allows you to use many more phrases all through the site and match what people are searching for.
The important thing to remember is that it is easy to connect phrases to make sentences, but difficult to make good marketing copy out of them. The larger the list to work with, the easier it is.