Sorry, I don't think cross hatching would look as good as some other ideas, because it would break up the shape of the patches. I stitched in the ditch on one I did, which emphasised each shape, but that was hand done. Or possibly a wiggly line down the middle of each shape, again that would emphasise the interlocking idea of the patches. If you want something more intense, then any variation of feathers on each shape would look great.