Here's a tutorial that I put together on stitching up a Rob Peter to Pay Paul block. The pieces were cut with an AccuQuilt Die Cutter, but the concept is the same.
The "trick" for me really was knowing which piece should go on top, slowing down, and holding the piece on top up & close to the needle. You'll see it. I stitch these without pins.
http://quiltpossible.com/12/06/67/