>>358688506
measure your irl body part by part, create debug boxes in blender of right size for each body part, scale avatar to your irl height, scale legs part to chest part to roughly fit your chest/legs ratio, then roughly match all of remaining body parts using boxes at reference. after that, realize your anime girl avatar doesn't quite work in those proportions and either discard changes or use clothes that work well with those proportions. shorts look neat on that, can also try unironic crossdressing tricks like pulling avatar skirt high up to pretend legs are visually longer than they are

i think most people who bother proportioning just find a good middle ground between how it feels and how it looks