Get a headband to match. I found this at target and it was already covered by cloth and that made it easier to sew my hearts to it at the end.
Using a tread and needle sew sequins to one of the hearts.
Keep sewing until you cover an entire heart.
Hold the plain heart under the headband where you want it to be.
Place the sequin heart on top. The headband should be in the middle of the two hearts. Sew the two hearts together. Make sure to pick up some of the fiber from the headband so that the hearts don't end up sliding down. The best way to do this is to tack the hearts onto the headband at the top and the bottom of the hearts.