Here is the Proven Tough Love Method of an Incorrigible and Probably Congenital Packrat-Slob Xtreme ComboPak
Get 3 boxes, bags, or spaces on the bed, it doesn't matter. Gather absolutely every cosmetic product you have together, and sort it all into 3 piles.
1) Items that you actually use with such regularity that you would grab them in case of fire.
2) Unopened items
3) Items that have already been opened but either did not work for you, or will work for you when you have changed dress size, or hair color, or corrected some complexion challenge, bought those lime green contacts, gotten that coveted invitation to the exclusive annual Electric Blue Eyeshadow Ball in your community, or otherwise do not fit into Category 1.
Take everything that is in Category 1 and put it in a small container that will fit in your bathroom and can be slipped into your purse.
Ruthlessly and relentlessly put EVERYTHING in Category 2, including those things that you just know will be in Category 1 as soon as you get a chance to see what all they go with, put it all in a Blessing Bag and get it to some ladies who need it and are unlikely to get it unless you give it to them. Holler if you really need instructions on how to do this.
Disposition of Category 3 is a Multi-Step process:
Immediately notify all your dearest friends and relatives who will not be alarmed by the possibility of using makeup, creams, potions and lotions that you have already opened, and/or used, preferably individuals who have been doing exactly that for some time that their presence at a Very Special Liberation Event is required. Mandatory, no excuses.
Cause some snacks and beverages to become present.
Collect some plastic grocery bags for guests who neglected to bring their own.
Arrange Category 3 in all its glory, into a spectacular array covering every horizontal surface in your home that is not occupied by snacks, beverages or plastic grocery bags. If you want, as an extra thoughtful gesture, before your guests arrive, you might try grouping products according to what you think will look good on whom. Caution: Do NOT do this if fooling with the products any more than necessary to spread them out might tempt you to lie to yourself that they are now, ever have been, or ever would have been, Category 1.
If you can do that safely, and want to channel your Inner Martha Stewart, you could even make gift baskets, and watch hilarity ensue as Cousin Mina shrieks "What in the name of all that is holy would ever make you think THIS color highlighter would make me look anything but greener than I already do!"
Encourage guests to try everything (put out lots of mirrors, including magnifying ones), and agree that Cousin Mina does indeed look greener than usual in that color highlighter, but it does wonders for your best friend's undereye circles.
Everything must Go. Each guest is under the sacred obligation to find someone else who can use it if they can't, but it must leave your premises.
Where appropriate, hint that this or that particular guest might want to hold a similar Liberation Event for her unconscionable collection of unused clothing. Or faux bling.
Or handbags....