I'm learning day by day, and I've been experimenting with different colors, scents, molds, etc. So far I haven't used any additives, but I'm thinking I want to try a few to see what the results would be. I've read what each of them do (vybar, stearic acid, uv inhibitor, universal additive, etc.), but can't decide which to try. What do some of y'all use? Thanks!