How to memorialize your angel

Darcy • 31 y/o happily married. Can't have a rainbow w/o a lil rain. 💦🌈 😇mom to 2 Angels &1 rainbow due 3/24/16. IUI/ Clomid
What did you all do (if anything) to memorialize your angel baby? My friend buried a medal next to her grandma and said doing that was cathartic.  I am thinking of releasing a balloon on my due date (Father's Day :-( other ideas? I'm not one for tattoos....