DIY Ring-A-Lings: Created by painting a metal washer with nail polish. Start with a base coat of white or yellow. Add colors, letting each coat dry before painting on top of it. Top the finished design with a protective coat of clear polish.
Could do these to go with a plant theme - in shape of leaf maybe. DIY How to make plantable paper seeds. These make great party favors and per the instructions, look pretty easy to make. You could do these in any color or shape that suits your needs.