It is mostly just backstitch, seed stitch, running stitch and some satin stitch. I haven't specified any colours, so use anything you feel like! I am trying to finish mine in time to put a pic up on Valentine's Day. I used a bit of light blue watercolour paint on the bunnies, then I used running stitch as the filling stitch for them. I am filling the inside of the heart with pink seed stitch, and I'm using satin stitch for the flower. I've used 2 strands of floss for everything except the bunnies, where I used only one strand for the outline and one strand for the fill.
I'll post some more pics once I've finished.