On every page that you targeted in the key phrase map:

1. Put the target phrase first in the title tag.
2. Put the target phase into the page headline.
3. Ideally, make that headline the only <H1> tag on the page.
4. Make sure the target phrase shows up in the first paragraph of text on the page.
5. Put a relevant image on the page, if you can, and make sure the ALT tag contains the key phrase.
6. Try to put the key phrase into other structural elements on the page, where it works. Headings, image captions, pull quotes and such are all good targets.
7. Try to have another instance of the phrase on the page in bold text, if it makes sense. Don't start jamming boldface type all over the page.
8. Review the page and try to make sure you don't go synonym crazy. If you're optimizing the page for 'bicycles', don't use the word 'cycle'. Use more pages to optimize for more keywords.

Note that I don't tell you a specific keyword density, or a number of words on the page. You should have as many words as you need. No more. No less. And you should use your key phrase where it makes sense.

Your content needs to read naturally to a human being and be valuable to them, while at the same time providing a decent amount of content that contains your keywords for the search engines.