Hey sprtsguy, nice piece. With one that size simply cuting into a four piece pie shape would give you some nice frags that would bounce back pretty quickly. Any smaller and you'll just want to try and at least get a mouth within the piece. This will also allow a quicker healing time, as it will still be able to physically injest nutrients rather than just depending on photosynthesis.
Typically with large pieces, you'll cut a ring around the center, then take that doughnut ring and cut it ilike you would a pizza/pie (will end up with hexagon shapes). They'll fill out and round up within a few months.
Good luck!
-Justin