Incorporating your chosen keywords into your page content is even more important that putting them into your meta tags when you are optimizing your website for the search engines.
After you have decided on a few keywords for each page of your website, you then need to review the text on each page and figure out how to incorporate those keywords into that page text.
You should sprinkle the chosen keywords throughout the text, not just mention them one time.
For instance, if you had a website about gadgets and one page was about wireless gadgets, you would then make sure that your content reflected this topic and included the phrase 'wireless gadgets' in several places.
As a side note, it is very important to make sure that you have text on every page of your website as that is what the search engines 'read' to really get an idea of what your website is about.
Do not simply list lines of keywords on your pages. If you simply list keywords on your website rather than integrating them into your text, your website could be banned from the search engines as this is considered spamming.