Use it Up Challenge

Organizing my bathroom last year made me realize that the sheer volume of products in there is pretty ridiculous. The bathroom is tiny to start with, but the entire shelf behind the toilet is completely full, as is the under the sink cupboard, and the shelf by the shower. There's an entire hatbox FULL of samples that need to be used.
This year, I decided to take part in a "use it up challenge". Basically, the goal is to use up all your products entirely, before purchasing new ones.
There are lots of variations, some are a hitting pan on beauty products, some are using up a certain amount in a year. For this, I'm choosing to use up everything I can, without abandon, and figure out what I really love using, what I can live without, and clear out space in the process.
It seems like a good idea would be to keep a list of things as they are used up, so if something is particularly awesome, it can be repurchased. If something is just kind of meh, or not amazing, then that won't be rebought.

I am super guilty of buying things just because they're new or trendy, and then I end up with 400 hair products because I switched conditioners after realizing I didn't like the one I had, or literally 10 of the same color of eyeshadow from 5 different companies.

I used up my first item this week, but it doesn't really count since it's my daily moisturizer that I have been using for years. It's the Nuetrogena sunblock one.
But I started actually using my Murad Vitamin C serum, and my Philosophy Eye Cream every day instead of letting them sit around.
I tend to keep samples of things, or don't want to use things up all the way, so then I end up with tons of half used products clogging up my space. It's silly. I bought the stuff to use it, or I got the samples to try it, so I need to use them up instead of hoarding them.

Just for good measure, this is a super embarrassing photo of everything that was in my tiny bathroom and that I plan on using.

Are any of you taking part in one of these challenges? Have you in the past?