When a lip product finishes, I don't throw cases if I haven't bought the new one yet. Then I put a yellow label if I didn't like the product, orange label if I'm neutral, green label if I'm satisfied, purple label if I like and blue label if I love. I know this sounds a bit weird for a person who says she's lazy doing make-up but there's a point. Making a list would be much easier but you may not find the same colour from the same brand. They discontinue some colours or sometimes even whole range or make little changes of colours or features. When I go shopping I take those cases with me, so it's much easier to find the very same product. I wish I had started labelling before, I can't still find the bright light pink lipstick I used ten years ago.