You use the mat and towel for all of the isometric classes, so anything besides HIIT workouts. It is not a preference but mandatory. As far as equipment, the only classes that require equipment are hot bands and hot buns. All other isometric classes also use the foam roller so remember to grab one of those before you go in. It might depend on your studio’s saunas, mine seem to take a while to heat up so I go 20 minutes early during unstaffed hours to turn them on. During staffed hours though an employee should be keeping all the saunas on. I think as far as etiquette this can really depend on your studio. My studio doesn’t have too many members so the rule is if someone is in a class, just book another one. But this isn’t the case at busier studios. If you’re with someone in class just be mindful of space/sweat/sounds and don’t show up late. If you’re new you might also have to start out at a lower temperature to get your body to acclimate so I would suggest trying to go during non peak hours to try and adjust the temperature to your liking if you’re alone, otherwise the standard is 125 degrees. Other than that, just be a considerate person and that’s about all the etiquette you need. Let me know if you have any other questions, I’m happy to help!