Adding a Related Posts Area to a Post (Mystile Theme)

In this latest post on woothemes:

http://www.woothemes.com/2013/08/how-to-create-a-unique-wordpress-website-15-top-hacks-for-canvas/

Number 13 shows how to Adding a Related Posts Area to a Post.

Does anyone know how to do this in Mystile so I don’t have to use a 3rd party plugin?

Thanks

http://wordpress.org/plugins/woocommerce/