1. "Match the foundation sample to your neck instead of your arm — your neck is a closer match to your face."
2. "Stop smiling when you put blush on — it will make it sit lower on your face. Always apply to a rested face."
3. "Putting highlighter on the tip of your nose brings all the attention to its widest part. Instead, only highlight the bridge."
4. "Not exfoliating your lips before applying a matte lipstick. If you have the time, put some heavy duty lip balm on — this way, your lipstick will glide on smoother and not look dried or cracked."
5. "Liquid liner should only be used for the top lids. If you want to line the bottom, a pencil works much better. But don't forget to smudge it out a little!"
6. "Not using SPF in your skincare regimen. It not only helps you age gracefully, but can also protect you from skin cancer."
7. "Most women pick the wrong foundation shade. When I worked in a beauty store, a lot of lighter-skinned women picked darker foundations to make themselves look more tan, but it just gave an orange, caked-on look, and darker-skinned women typically wanted shades that were way too light for their skin, giving them a gray look to their face."
8. "It might be a time-saver to just use one brush for most of your eyeshadow, but using the same brush you used for a dark color for blending is why your eyeshadow comes out looking murky. Get cheap brushes if you don't want to spend the money on a fancy set — even they will serve you better than the fanciest one if it's dirty!"
9. "Not knowing your own skin type. You'd be surprised how many people have come to me thinking they have an oily skin type, but the second I put a matte foundation on it, their skin started flaking off!"
10. "Drawing your eyebrows too close together."
11. "The eyeliner placement I call 'the Britney.' If you're going to use eyeliner on your bottom lid, it needs to be placed on your waterline, not below it. That's why it always smears and looks like you wore it overnight and just woke up."
12. "Not taking your makeup off at night. Sleeping in your makeup ages your skin by seven days!"
13. "When using eyeshadow, don't just put on one shade. Adding an undertone or overtone makes the shadow look much more full and pigmented."
14. "Not blending your makeup into your hairline."
15. "Neglecting to clean your tools. So often I hear people complain about breaking out on their cheeks or suffering from congested skin, and I always ask, 'How often are you cleaning your brushes and beauty blender?' And they reply, 'Oh, I'm supposed to clean it?'"
16. "There are very few people who should be using dark brown and black brow pencils. Many people using those put it on too heavily, and it looks awful. Go lighter. You can always layer if you need it darker, but if you start with a too-dark pencil, there is no way to correct that."
17. "Forgetting to drag your foundation down your neck. If I see one more woman with a foundation line on her jaw, so help me."
18. "I'm a theater/SFX makeup artist for musicals, and one of the worst things you can do both on- and offstage is to not blend your makeup properly, taking the time to build up intensity rather than smearing it all on at once. Nothing says 'amateur' more than unblended eyes and contour."
19. "Highlighter is meant to highlight, not to paint your whole face with."
20. "Wearing a full face all day, every day. Your skin needs a break. Alternate doing the full face with a couple days of just brows, concealer, and powder."
21. "Sucking in your face when you contour. When you suck in your cheeks, your skin moves up, and you end up putting the contour in the wrong area. Instead, look straight ahead in the mirror, imagine a line going from the tops of your ears to the corners of your mouth. Perfect placement every time."
22. "Don't forget to clean your hands thoroughly before applying anything onto your face, especially if you have long nails."
23. "Not making sure your primer and foundation will work together. Oil and water don't mix, of course, so your primer and foundation should both be either silicone- or water-based so your foundation doesn't end up patchy and wonky."
24. "When people try to find hacks to do their makeup quicker. To be honest, just spend the time on your face! No hack will give you as good a look as time."
25. "Don't forget to always have two different foundation shades — summer and winter — that you can mix to customize for the in-between seasons, too."
26. "When people try to do YouTube makeup for everyday life. There's a reason why there are artists who specialize in TV and event makeup. It looks good on camera, but not necessarily in real life."
27. "Neglecting your under-eye of eyeshadow."
28. "Packing on too many products to try to create a flawless look that's unachievable. There's no such thing as completely erasing pores, lines, or texture, and a lot of times when you see that, it's through good lighting or Facetune!"
29. "Don't forget to do whatever makes you feel beautiful. Does a full beat do it for you? Great! Just lip gloss and mascara? Awesome. If it makes you feel confident, that's all that matters."
Some responses have been edited for length and clarity.