Knit both sides of the heart.
Face the RS of each heart together and sew a portion of the edges.
Flip the heart right side out and embroider your choice of face.
Flip the heart inside out and continue to sew around the edges, leaving a small hole to stuff.
Flip the heart right side out again.
Fill with stuffing or rice. (I filled mine with rice that I sprayed with my perfume for that girlfriend-smelling hacky sack feel.)
Sew up the hole and admire your work.
Note: My hearts came out in different sizes because I was stubborn and wanted three different colors. Make sure to take that into consideration.