Step to optimize your keyword density as below:
› Increase the use of image on your post and include the "alt tag" and the "title tag" and name your picture after your page title name.
› Use Video
› Use Tags or Label, with many tag on your page or index index page will increase the number of your keyword or keyword phrase.
› Use Popular Post, Recent Post and Related Post on your index page it will enrich your keyword
› Use anchor text link that refer to your keyword page title.