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.
I love using mason jars for decorating and a seemingly endless supply of craft projects. But rainbow tinted mason jars, just like the vintage ones you can never find anymore? This one might be my favorite project with mason jars yet!