Ever wondered what goes down when idols arrive at the hair salon before a schedule? Park Naeju—the famous Bit&Boot hairstylist to groups like BTS, EXO, NCT, GOT7, THE BOYZ, and MONSTA X—revealed the four-step process in a recent YouTube video.

Step 1: Washing the hair

Because of their busy schedules, idols are often very tired when they arrive at hair salons like Bit&Boot—hence, they tend to show up with very messy hair.

“They show up like this.” – Park Naeju | *내주제에 Dare U Naeju/YouTube*

Hairstylist Park Naeju also says that idols often wear hats to cover those messy, dirty locks, which means they have hat hair on top of that. As such, washing the idols’ hair with shampoo is unsurprisingly the first step.

Step 2: Applying mousse

After the idols get their hair shampooed and dried (and often, their makeup done), it’s time for the real styling to begin. Naeju revealed that the next step is to apply mousse to prepare the hair, then dry it again to set the mousse.

This makes the idols’ hair stiff and unmoving; if you’ve ever wondered how idols manage to give powerful performances without their hair flying everywhere, there’s your answer.

Step 3: Creating a style

After the hair has been prepared with mousse, the idol’s hairstylist will begin creating the actual style they want for the performance or broadcast. This could be anything from an intricate updo for long-haired stars to a natural look for short-haired idols. For the purposes of his demonstration, the popular hairstylist decided to give his client an NCT Doyoung-style hairdo.

When styling the hair, Naeju straightens any loose strands with a dryer, then uses a half-moon iron to add volume. Adding volume can be essential for idols whose hair has become limp or thin due to excessive dyeing and styling.

Then, after finishing the style, he takes the necessary precautions to make sure idols’ forehead sweat doesn’t jeopardize their look. Tidying up the roots with hairspray creates a barrier from the sweat during a performance, and it adds texture to the idols’ hair too.

Step 4: Finishing with wax and spray

Finally, it’s time to set the hairstyle for an extra layer of protection during performances. According to Naeju, stylists have to choose their waxes carefully; while a hard and sticky wax will firmly fix the hair in place, it can also mess up the style and lead to a poor image for the artist in question. After all that, another layer of hairspray finally completes the look.