If you don't follow any makeup artists on Twitter, you're missing out -- they're a great source for all sorts of tips and product news. One of our hands down favorites is celebrity makeup artist Fiona Stiles (@fionastiles). Her comments are informative and honest -- plus, she tweets with her famous clients about everything from eyeliner to "Game of Thrones." It's like eavesdropping on an insider gossip session.

In recent weeks, Stiles has been prepping Elizabeth Banks for her "What to Expect When You're Expecting" premieres and creating gorgeous editorial looks on it-girl du jour, Jessica Chastain. Need more to convince you of her awesomeness? How 'bout the fact that she's Halle Berry's go-to makeup artist? Thought that might seal the deal ...

Between photo shoots and appointments, the makeup guru found time to talk to us about her must-have products. In no particular order, these are the nine essentials she has on hand at all times. Whether you're a makeup pro, or you're building your makeup bag from the ground up, Stiles recommends these items be the cornerstone of your collection.

Skip ahead to see celebrity makeup artist Fiona Stiles' product picks.

Stiles' favorites range from drugstore brands to high-end indulgences -- but, hey, if they can make Halle Berry look, well, like Halle Berry, we want to try them. Think you'll want more than nine products,to flesh out your kit? You can always follow Stiles on Twitter for even more celebrity makeup artist recommendations.

When it comes to lip balm, Stiles is a connoisseur. So it's no wonder that her favorite is the vaguely pink, rose-scented By Terry Baume de Rose, $60. "Lip balm is my desert-island item -- the one thing I would take with me anywhere," says Stiles. "I love this product."

Of course Stiles uses a zillion brushes when she's working on clients, but for the rest of us she recommends the EcoTools Bamboo 6 Piece Brush Set, $12.99. You get just the essentials -- powder, concealer, shadow, eyeliner, and a comb-brush duo -- and while they're eco-friendly and affordable, they're just as good as the best makeup brushes on the market. "This is everything you need on the go," says Stiles. "Plus, the set comes in its own cute cotton and hemp case so your brushes stay clean -- so important!"

If Stiles were to use just one makeup product in the morning, Anastasia Brow Gel, $21, would be it. "I always set my brows," she says. "This gel never flakes, and it keeps your brows in place all day."

While lots of makeup artists use sponges, Stiles is dedicated to one in particular: the Beautyblender Sponge, $19.95. "It allows you to apply your foundation flawlessly, thinning it out where you need less and leaving more coverage in spots that need camouflaging," she says. "It lasts forever and it's really adorable to boot!"