Ing81, as to ‘mixing’ them, I would not do that in the bottles. More of layering on the skin, such as IS/a and IShine on differing patches of skin or back of the knees as some posters like to do.
Here is why AD suggest layering on the skin and not in the bottle. Of course, more Advanced User’s do mix in a bottle different molecules and components and that has it’s place as well. But, for you, I’d suggest layering as most of the users do on the forum.
Here is the why and how: