hip dips and prominate collar bones can be a bit confusing, there's an idea that "only super skinny" people get these things and only women get hip dips, that is wrong! men can have hip dips too and having prominate collar bones doesn't neccerally mean someone is very thin.

collar bones

collar bones are bones at the upper chest just under the neck, they are highly palpable usually.(meaning, they are very "feelable" since they are close to the skin and typically there's also not a ton of fat stored in that area) and they can change in appearance depending on pose and such. now if you're drawing someone who's plus sized, their collar bone likely aren't visible but for midsized (midsized is a term usually used for people who aren't skinny but aren't plus sized ether) and thinner people it usually is.

example/reference photos of a collar bone area (my own collar bone area, I do have clothes on, the photos are just cropped)

I put this under a spoiler just in case someone finds this sort of thing weird/gross to look at and they don't wanna see this sort of thing.

Spoiler

hip dips

now for this imma show a different type reference and not one of my own body, but we'll get to that in a moment.

hip dips are dips at the hip area, they don't neccerally mean someone is skinny, they are natural and caused by a variation of the human skeleton. they aren't exclusive to women nor does every human on the planet have hip dips

example/ref photo

imma be honest with you, you can draw your character with hip dips or don't, i've seen some people say that if you don't draw a woman with hip dips it's "not accurate" or somehow offensive to women or it's fan service but that's not really true. it's just a variation in the human body, maybe working out and building muscle will make it go away, but at the end of the day it's just a harmless anitomical variation in human anatomy that men and woman can get.
if you draw your character in something like a skirt, it won't even really be visible, it's usually only visible in things like leggings and swim suits.

outro

I hope this was helpful to someone, these were just some things i've commonly heard and such, please be nice in comments and don't like, make fun of these things. I think the hip dip diagram in particular is especially helpful tbh lol.