Thanks for all the kind words.
I think most of the questions have been answered (thanks for those of you MareMare and others who took the time, I haven't been around here much!)
But just a recap because I've seen some common ones:
To use: wet lips with water, gently rub scrub on your lips with your fingers, rinse with water. Apply a nice lip balm after if you like.
Ingredients: You really don't have to add anything besides sugar and some sort of oil. It's nice to have some flavor & scent though. General rule when choosing things to add: ask yourself "would I put this on my lips or would it be harmful/gross?" If you'd put it on your lips in general, it's probably okay to go in your scrub!
Storage: Unless you start adding crazy ingredients that would cause it to be perishable, it keeps well stored at room temperature in an air tight container. Because it contains oil, storing it in the fridge would make it keep a little longer, but it's not necessary. It will keep well like this for quite some time, but with all homemade B&B, the fresher it is when you use it the better!
Hope this helps! I'm glad so many people have had so much success.