The Disappearing 9 Patch block is great. Very easy to make, but looks quite impressive when done! I first discovered it in a book called "Magic Pillows, Hidden Quilts" by Karin Hellaby. I've since seen it on line in various places and using different names. Here's a little tutorial on how to make a scrappy version.

Firstly - select and stitch together 9 squares. For maximum contrast try and get 5 darker prints and 4 lighter prints arranged with the darker prints as the X of the 9 patch.

Square this up, then cut through the block both vertically and horizontally. (My starting squares were 4", so I squared up to 11", then cut to make each new block 5.5".)

Turn blocks to rearrange pattern.