For those with steel doors, take one of those business card magnets that we all seem to acquire. Cut it in half horizontally. Punch small holes in each corner. Use these holes to attach the magnet to the back of the quiltlet...one in each corner. Works great. We put magnetic picture frames on the back side of FIL's bathroom door. With the door closed it was a great backdrop for his grands' and friends pictures.
Can you use command hooks on laminate doors? If so the very lightweight clear ones are heavy duty enough to handle those little gems. Take 2 small squares....2.5 or 3". Fold each on the diagonal to create a HST. Before sewing on the binding place these in the upper right and left hand corners. Attach the binding as usually encompassing the raw edges of the triangles in the corners. This creates a little upside down pocket to insert a wooden dowel across the top corner to corner. Bamboo skewers are a great size and are easy to cut to size. Use the skewer to hang on the little hook.
Check this link out for other ideas:
https://thesewingloftblog.com/how-to-hang-your-quilt/