The answer to this question is simple: one. A single web page should not be optimized for more than one keyword. Of course, that keyword can consist of several words, for example “buy inexpensive golf shoes”.
If you have optimized one of your web pages for that keyword (it’s actually a key phrase) then you should not optimize the same page for other keywords.
It’s much better if a web page is highly relevant to one keyword than somewhat relevant to many search terms. If you concentrate on one keyword per page then it is much more likely that your web page will get a top listing on Google and SEO friendly for that keyword.
If you also want to get high rankings for your other keywords such as “brown golf shoes”, “golf shop” or “golf equipment” then you should optimize other pages of your website for these keywords.
You will get the best possible results if you optimize different pages of your website for different but related keywords.