Make the page relevant to the keyword, and make it as useful as possible for the human readers. Also ensure that you don't have any html errors (as that will stop the spiders from reading your site).

For a few years search engines have been pretty clever, and analyse pages in a very similar way to what a person would - so if it is good for people, it is good for the search engines.

There are tricks to fool the search engines, but they vary for each search engine, and change every couple of weeks - and if you get caught using those tricks after the search engine has been altered to spot them, your site will be blacklisted.

In addition to that, rankings depend a lot on the users - based on the results they ignore (rank goes down), pages they actually visit (rank goes up, especially if they return to the site later).