Tartan has given you great advice. As to sewing the V, in addition to the short stitch length, I would take only 2 stitches there for your inverted point since you are doing small hearts. Larger the project, you could get away with maybe 3. Then clip quite close to that seam line careful not to cut THROUGH the stitching. You could also 'grade' your seams at that V - cut the bottom seam allowance shorter than the top layer, thus helping things lay a bit flatter.