I used the 'Lost and Found' fabric by My Mind's Eye. This block I designed is so easy, yet the options are limitless. Check it out and feel free to leave a comment here or on their site.
In order to see the tutorial, when you get to the Riley Blake blog, just click on the 'Cutting Corners College' tab at the top and you can see the full instructions there.
I think this is my favourite quilt I have designed for them. I know that my mom is going to use it when she does quilts for charity, as it is easy, fast and has a fun pattern when assembled.