The last thing a yogi wants to do is create stress–or talk about it. But when we asked these top instructors to tell us what they were thinking, they divulged a few pet peeves (as well as some secret tips for Zen seekers). Here’s what kept coming up.

1. If you’re more than 10 minutes late, please consider skipping the class–even if we welcome you in.

“Coming in late can not only be distracting to the rest of the class, it can also lead to injury, especially if you’ve missed the warm-up and sun salutations. Peek into the room. If people are still sitting on the ground, then it’s fine to join in. It’s even better if you can wait until we’re getting up because then it’s less disruptive for everyone to move over.” – Kristin McGee

2. Bring your own mat.

“Most studios are good about cleaning them, but sometimes they just use a Handi Wipe. Regardless, it’s bad enough putting your face where your feet were. When you borrow a public mat, you’re putting your face where other’s people’s feet were.” – Clio Manuelian

3. …But for the love of Buddha, please wash it regularly.

“So many people sweat all over their mat, then roll it up, throw it in their car and roll it out for the next class. If the mat’s been living in your car for three months, we’ll all smell it. Take it into the shower with you once a week or so and dry it in the sun.” – Annie Carpenter

4. We notice your Mrs Clooney underwear.

“We don’t want to see what you’re unintentionally showing. As teachers, we like to think we’re beyond that, but it’s still distracting.” – Annie Carpenter

5. Teaching certification is essentially meaningless.

“It can be easy to get a certificate, and almost everyone who teaches in a health club or studio probably has one. A better way to find an instructor is to ask around. Good teachers have followings, and you hear about them. Also beware of teachers who, when you tell them you have a pulled muscle or a sore shoulder, just tell you to keep pushing and breathe through it. That’s usually a sign they don’t know how to deal with the problem.” – Barbara Benagh

6. The whole class heard you make that mortifying noise, but it didn’t bother any of us.

“Passing gas is so common in yoga. You’re doing twists and forward bends, you’re moving around your internal organs and stimulating digestion. On one hand, it’s a good thing to relieve some of that gas, but of course, it can be quite embarrassing. I just ignore it and move on.” – Kristin McGee

7. The whole class can hear you breathing, and it bothers every one of us.

“You’ll get these guys who breathe so heavily it sounds like they’re in a porn movie. I’ll tell them, ‘It’s not supposed to sound like gasping air, but like you’re enjoying the fragrance of an amazing wine.’ When everyone does it together, it sounds like an ocean.” – Kristin McGee

8. We can tell when you’re hungover.

“You can smell it on students: Their sweat gets that metallic scent. It’s not my place to call them out on it, but I’ll probably suggest that they should drink more water.” – Annie Carpenter

9. Please save the essential oils for your home practice.

“I’ve noticed that people become very attached to wearing essential oils during practice, and they’re even stronger than perfume. Popular scents like bergamot, patchouli and lavender–while some people love them, others hate them, and you don’t want to overpower everyone in the class.” – Kristin McGee

10. We’re sometimes appalled at your lack of consideration.

“I often see people leave the room to go to the bathroom by walking across other people’s mats. If you need to leave the room, please walk on the wood floor. And please also open and close the door quietly. Being mindful in transitions starts from the time you park your car in the lot to the time you leave.” – Annie Carpenter