does anyone have any advice on how to make teens believeable for me?

I go into CAS for most teens and make heavy edits. For boys and girls I make them both considerably thinner and gawkier than default (which I realize isn't always the case, but I'm just trying to create a separation). I give boys narrow shoulders and a shallow chest, and sometimes hunched-over posture. Same thing with breasts and hips on girls.

The default difference is too subtle at a glance, and since we can't edit height (without mods) this is the best way I have found of making teens physically unique.