I have the same vanity from IKEA, and I love it! (pain in the ass to put it together though).
And the first thing I did was buy little dividers from IKEA to store all my make-up in. My top drawer holds my entire stash too.. I was hoping I could squeeze my perfumes in there too, but that plan failed so I keep them all on top of the vanity where you have your brushes.
Anyway, it's a great vanity, I'm really glad I bought it.
Oh and your collection...