Wow, veronikawithak, kudos for taking that challenge! I'm already excited what you might report about it.
Since I'm not only a makeup hoarder but also have a slight problem when it comes to shopping clothes, I'm also trying to change my attitude towards shopping for clothing. Formerly, I mostly went to H&M during my lunch breaks or after my courses, and I'm passing several shops on my way to uni/work. I quickly bought some ten-euro-shirt every week, honestly to compensate stress and so forth. Looking back, all those items bought spontaneously and in a rush just sit in my closet. Or I exchanged them for something different a few days later/got the money refunded. Now, I'll go on a "real" shopping spree every month(?) and I'll take enough time to consider whether I'll buy something. I bought three knitted dresses for wintertime yesterday, and a cardigan, but I also picked three old pieces from my closet to give away for charity (in my town, there are special plastic bags in the mail. Old clothes can be put into these and the bags will be picked up by volunteers, so there's no effort at all when I wanna donate clothes, which is great).
Although my skincare/body product stash is quite okay, I had to toss a shower gel (an expensive one by Soap & Glory) because it suddenly looked really disgusting. I also tossed two mascara samples because they had been opened for 6 months and put a third tube of mascara into my back-2-Mac box. Well, tossing stuff is not the solution for my collecting problem, but it feels nice anyway. And I'm about to finish my first lipstick ever!!! It's Patisserie and I got it via back-2-Mac in, like, 2008, so it REALLY has to go now. It's surprising to see how long even those bits at the bottom of the lipstick tube last, I'm scraping the product out of the tube with a q-tip now, and that stupid lipstick won't get finished...so I've definitely learned that I shouldn't be afraid of using my stuff - even when a lipstick's seemingly empty, there's still so much left over!