what every beauty kit needs--according to the people who know it best.

We logged hours backstage during Fashion Week, checking out the beauty looks at Marc Jacobs, Altuzarra, Rag & Bone, and so many others. (No really, we were at dozens of shows.) One thing that stood out to us was that no matter the show and no matter how over-the-top the style, the makeup artists, nail artists, and hair stylists that populate backstage all used some very useful, functional tools. Some might be super insider-y (like the Japanese brush one hair stylist at Boy by Band of Outsiders told us is the only one he uses), but most are available at your local drugstore--or at least, online. So even if you're not ready to commit to the '60s eyes at Marc Jacobs or the messy top-knots at Katie Gallagher, you can add any of the following tools to your beauty kit and know you have a pro-grade arsenal. And when all else fails, more than one major stylist told us that their favorite tool of all is their hands--thanks, Guido Palau!

The Tool: A Lip Brush
The Pro: Katie Hughes for Butter London
The Show: Erin by Erin Fetherston
The Tip: "It really helps make your manicure perfect. You can dip it in some nail polish remover and clean up the edges. This is one of the best tips I could ever give somebody, because everybody's like, 'Oh I can't make my nails look nice!'"

The Tool: Nars Eyelash Curler
The Pro: Tina Turnbow for NYX Cosmetics
The Show: Erickson Beamon
The Tip: "Eyes are my favorite thing, and lash curlers are awesome for opening the eye. I've been really into Nars' lately, just because I stopped using Shu Uemura's a little bit--I was like, Let's try another one. And I liked it."

The Tool: Mason Pearson Popular Brush
The Pro: Pearson Knight for Aveda
The Show: Boy by Band of Outsiders The Tip: "I use it always. That's my everything!"

The Tool: A Mascara Shield
The Pro: Gilbert Soliz for Sephora
The Show: Charlotte Ronson
The Tip: "Hold a rubbery lash guard underneath the lashes and then dab a few drops of mascara on the back of your hand. Using a small brush--an eyeliner brush works fine--paint your bottom lashes. You get the perfect amount on your lashes without any clumping…plus, it doesn't get all over your skin!"

The Tool: The Beachwaver
The Pro: Sara Potempa for Aussie
The Show: Erickson Beamon
The Tip: "It's a curling iron I invented and it has a left and right button--you basically clamp it on the bottom [of the hair] and it rotates and curls all of your hair for you. It's like a five-minute beach waverer. I use it on every celebrity--I just did Nikki Reid for Fashion's Night Out. I had one of my clients who was going to something super-easy and she was like, 'Oh I'll just use my Beachwaver!'" I'm replacing myself with my curling iron!"

The Tool: Almay Oil-Free Makeup Eraser Sticks
The Pro: Romy Soleimani for Stila for
The Show: Cynthia Rowley
The Tip: "This is the bomb. You can put it in your clutch bag when you go out. I give them to a celebrity if they need to touch up. If you're doing liquid eyeliner, if you're new to it, you can make it sharper. Or use it if your shadow falls. Some of these girls have done so many shows that's there's liner stuck in their lash line. You can remove it easily with these."

The Tool: Lancome Dual-Ended Cheek and Contour Brush 25
The Pro: Daniel Martin for Lancome
The Show: Chris Benz
The Tip: "We're using the larger, angled side to apply shadow to the crease of the eye."

The Tool: Bioderma
The Pro: Gordon Espinet for MAC
The Show: Alexandre Herchcovitch
The Tip: "French drugstore products [like] Bioderma, because it's like water. It's cleansing water that you can use on anybody's skin and it has no irritant in it whatsoever. These girls have makeup on, makeup off so many times a day, so we're so careful with the cleansing part of it."