I just use my large square to cut wonky blocks. If it is a sampler block,I add sashing strips all around the edges and then set my square on top of the block but turned to the angle I want. You can mark the angle with painter's tape to do them all the same or just do them all free hand. I see you have an idea in mind but Quiltmaker May/July 2012 issue had an amazing pattern for a skateboard quilt called Kickflip. The pattern was designed by Denise Starck and it is easy but cute. You might want to look at it for inspiration. I have set my issue aside because it has 2 patterns I want to try, the skateboard and the running shoes.