It's neat if you're cutting from random scraps, but if you have 10" squares like she uses in the video, it's easier to just do this (see link below). No template is required, and all the blocks will have slightly different shapes.
You can use any size square, really. It doesn't have to be 10".
http://mselaineousteachessewing.blog...ilt-block.html
But, like I said, if you have a pile of random scraps, it would be neat to have a template so that you can cut them into the exact shapes needed for a perfect fit.