That’s a good strategy. I’m going to focus on finishing my opened ones then I will adopt that rule.
It's sometimes hard, especially when you have new lip glosses on your desk. But it is so satisfying to open a fresh one and finish it. It usually doesn't take that long to finish it and I know that the products and fresh and hygienic. I try to have different colors, i.e. Garconne and Nana. It really works for me, keeps my stash at a manageable size, and it allows me to finish products on time.