For the sake of hygiene, you should wear underwear If you think that wearing tight pants will have ligature marks, you can change it into seamless underwear.

Bottomless socks made of nylon or spandex keep their original elasticity and shaping properties. But nylon is easy to break, and it is common to scratch and break on sharp objects. Cotton-wool blended bottomless socks have better warmth retention effect.

The top (waist) of tights is very elastic. The part that covers the hips is thicker than the legs (except for some dance purposes). The crotch bottom is also a solid material, usually cotton, which can keep the genitals cool. Legs and feet, all the way to ankles, are made of the thinnest weave.

Reference: Baidu Encyclopedia-Tight pants