I stitched around the entire heart and made the point square by one stitch instead of a sharp angle. Then I slit the back open! I couldn't use the envelope method with this shape and for more primitive pieces I some times would slit the back and use a muslin patch. The heavy fused facing prevented the fabric from tearing open even more when trying to turn it right side out. Before doing that, I pinked the seams instead of clipping/notching, and I cut a piece of quilt batting to fit inside the stitches, and then cut the edges on an angle to bevel the bulk.
Once turned right side out, I inserted the batting and used a few more pieces where needed, made a patch, and used the double fusible (Trans-Web) to glue it.
You can see that it's not very puffy, but enough, and I steamed it when completed. So where do I put it now? I still may attach a hemp cord and hang it but started playing around to see where I'd like it.