Fill a jar with Valentine fun. Use a variety of objects - heart shaped - stuffed, wooden, resin, clay, beads, felt, foam, handmade, store bought; Valentine colors like red. pink, purple and white - ribbon, washi tape, lace, pom poms, beads; Valentine related objects - rubber stamps, charms, sticker flakes, etc.

Glass or plastic jar with lid (plastic will be lighter to ship) - you can probably find a plastic jar at the Dollar Tree. If you use a jar that held food, clean it out real well and let air dry with lid off. Decorate the lid - ribbon, paint, washi tape, add something cute to the top - silk flower, wooden or resin heart - something cute that goes with the Valentine theme.
I am sure there are many more ideas that could be used to make this jar wonderful - make it something that you would be happy to receive.