how do you optimize your website for keywords?

Make a simple sheet: every important page in one column, its one main keyword next to it. If two pages want the same keyword, merge them or change one, otherwise they compete with each other. Then on each page the keyword goes in the title, the H1, the URL if it's a new page, and the opening paragraph. Internal links pointing to that page should use wording close to the keyword too, that part gets forgotten a lot.