I belong to a group called Technique Junkies and this is where I learned this one. www.patstamps.com. It's awesome!
What you do is score your paper vertically then horizontally, on both sides so the markings are deeply etched, in 1 inch increments, then lightly swipe an ink pad over it to highlight the blocks. Stamp your image on top, again using even light pressure so as not to get ink in the scores. You can also use a white pen to emphasize the blocks.