It helps to remember that girls are people. This video explains the secrets though (yes it’s the infamous CollegeHumor skit, which apparently needs to make the rounds again:-P).
Pro-Tip: even guys that don’t belch and fart and spit and pick their nose and scratch their balls or pits and stuff literally everywhere they go without holding back can also look just as classy too:-). Also, again even as a guy, consider wearing an undershirt to not show nipples.
It’s not about girl vs. guy, it’s about classy vs. not.
Don’t argue back - just do whatever you want, but you asked the entire Fediverse and I answered.