You start with the spine ---___----_____-----____ (pretend this is a curve, then you do the half-heart shape coming back down, going to within about 1/4" of the line, backtracking on the "straight part of the half-heart, until you can roll into the next one....continuing until you have done the whole length of the spine. Then, you tie off and start the other side of the spine.....

Thanks for all of the suggestions. :-)