You should use keywords in such a way so that it will cover almost 5% of the content of your web page. You should use it within a range of 3% to 6%, neither more or less. If you are using keywords below this range, it doesn’t get indexed by web spiders and if more than this range is maintained it is considered as spam by web spiders.
The keywords which you provide should be there in the title of the detailing and also in the title of the web page. You should not put too much of keywords in the title of both content and web page.