One of the best benefits of purging a collection is suddenly finding things that you once used all the time or were really excited about when you bought but somehow made their way to the back of a drawer instead of onto your face.
It's inevitable when you have an unnecessarily large amount of the same thing that shades and formulas get neglected. As part of my ongoing mission to use more of my stuff and part with things that don't make the cut I've pulled a selection of things to start playing with.