Stack and Whack is a quilt design that looks like a keleidoscope when the blocks are sewn together.
It really is easier to have someone show you or take a class. It is real important for the effect that you line up repeats in the fabric so that it looks like there are several of the same image in each block.. hope that makes sense. There are specific ways to cut the repeats, line them up and sew them together. It's not really hard when you understand what they are trying to show you.
I have done several, but if I haven't done one for a while, then I do have to go back and refresh my memory...maybe it's my old age..but it is so much fun seeing how they will look.
I have a mirror that has a fold to it so I can preview fabric to see if I like how it would look...