you always have a backup. I have backups of most products I use. I like to think it's because I'm organised, but it's probably because I can't resist an offer, so stockpile when there is one. I don't do this as often with makeup, though, because it takes a lot longer to finish, and I change it up more regularly. There are a handful of products I do keep multiples of, though. The ones above are the ones I currently have in my stash.
ELF Studio Eyebrow Kit in Light // I've been using the eyebrow kits from ELF for about 4 years now. I used to use the shade Medium, but switched to Light a couple years ago, which is a much better match for me. As well as being the right shade, both the wax and powder are pigmented, and last all day. The actual kit takes an age to use up, and for less than £4, it's great. The UK site is no more, unfortunately, but hopefully the brand will have a new distributor in the near future. If not, there's always eBay, which is where I bought the one above from.
The Body Shop All in One Face Base in 02 // I feel like this is the most mentioned product on this blog. I've been through so many, and always add one to my order when there's a particularly good discount code. It's soft and leaves you with a velvety matte finish, but what I like most about it is that it provides you with a little coverage. You'd think that it'd look too heavy on top of foundation, but it doesn't. It just looks natural.
Maybelline Eye Studio Lasting Drama Gel Eyeliner in Black // This isn't a product that I usually have a backup of because it's only become an everyday staple in the last six months or so, and one pot will last ages, but I bought an extra when there was a great deal on a couple months back. I used to be too lazy to bother with eyeliner, specifically gel, but it makes the world of difference. This one is jet black, creamy, and stays in place all day. The brush it comes with is good, too, and is the one I use daily.
Maybelline Mascaras // I always have at least one Maybelline mascara in my stockpile. I actually have four different ones on the go at the moment, so am keeping the two above sealed until I've used them up. Again, the reason for buying them was because of an irresistible offer. The Rocket is probably my favourite (along with Sensational now) and I bought The Colossal because I haven't used it for a few years.
I switch up the other makeup I use too often for me to get through one product in particular. I am tempted to buy a replacement for my L'Oreal Infallible Foundation in Porcelain, though, because it's the lightest on the highstreet, meaning it's the best match I've found.