Draw cross-lines where you want the heart and stitch down one side of the heart. Turn the guide around, align the cross-lines again and stitch up the other side of the heart. No crossing of the hands.
We suggest getting some Grip Tape for a better hold on fabric.
These rulers are cut in our 1/8" sea-foam colored plastic for domestic machines. If there is a size you would see made available, let us know.