To do it yourself, simply use a ruler and pencil as a guide to measure and space out a grid of holes. Knot your string and start from the back of the canvas and add in the design of your choice. These detail shots should give you a clear idea of how I made this way easy string art design. Feel free to print the photo below to use as your guide to create your own.
I kept mine simple and clean, but go all out and keep adding layers for a more intricate design.