It never hurts to have a little bit of luck on your side! These mini-vial charms take minutes to make, and would be perfect little St. Patrick's Day party favours. If you don't mind a little mess, this is a fun craft for older kids as well, although you might want to glue the tops down during assembly to avoid wishing dust all over the house. :)
Some craft supply mini-vials come with charm stoppers; however, if your mini vials are versatile but basic bottles with cork stoppers (like mine), you can easily add an eyelet to the top using an eye pin through the cork. Depending on the length of your bottle and pins, you may want/need to trim the end of the eye pin. Glitter is best added using a funnel, and if you don't have one that suits, you can make a basic funnel simply by rolling up a piece of scrap paper and taping it into an open cone shape. I suggest working on some scrap paper as well, to make clean-up quick and easy.
Make rainbows by incrementally adding layers of glitter, ensure the vial is full to prevent mixing afterwards, and secure the cork to hold everything in place. Use rainbow glitter for a multi-colour mix, stick with traditional green or glittery gold, or create individual vials in all sorts of different colours so that everyone can have their own unique bit of the rainbow.