You have to have a lot of patience to air dry salt dough. I don't have patience so I cook them in the oven for a couple of hours. I used a straw to make a hole in each of the hearts. So we can thread them to make ornaments, necklaces etc.
We painted them and added some glitter. As we painted on both sides we slid them onto a skewer to dry. We used two glass jars to keep the skewer balanced.