If there’s more than just one or two uses, I’ll cut the tube open — or if it was really expensive!
I have used sugar to exfoliate my lips, olive oil to remove my makeup (and in a pinch, I will rummage through anyone’s cabinet for this if I need to remove my makeup!), and I have also done an aspirin mask a few times. I can’t think of anything else, though!
I don’t mind if something stains my skin for a few hours post-removal, but I don’t want anything staining for 24 hours afterward, because then that interferes with what I want to wear the next day. When a lipstick stains, it’s typically a good thing, since it really enhances the longevity of the product, but it seems less valuable with other product types.
I make sure I am well-stocked in SPF at all times, especially ones that dry matte, because that’s what I look for in a sunscreen I layer under makeup. If I’m doing full makeup, I try to build makeup in layers, which means using primers and powders to set anything liquid/cream. For lighter days, I opt for tinted moisturizer over regular liquid foundation. I don’t really go to the beach, so waterproof makeup is not necessary.
Lots and lots of variety! I have found that–after being a long-time MAC user–variety is important. It helps you learn what you should expect in products, what really works, what doesn’t, and what’s worth it. I don’t have something from nearly every brand, but there is definitely diversity in the products I have.