my suggestion is also to use the eraser and get rid of a lot of the extra lines you have . you can carve out shapes using the eraser as well. think of it as a brush that paints white.
like in this area right here
there's a lot of marks that don't have to be there.
well, there were plenty of lines on her body prior to its current state. not trying to be defensive, but i'm just saying those lines are there because the picture isn't finished. i've been using the eraser like that to edge out all of the earlier and excessive lines on her torso and arms.
mainly i think your biggest issue is the overall construction of the anatomy. things don't quite match up right, you've got body parts that aren't joined correctly that differ too much in size. individually they work, but in context of the entire body they don't. a good way to avoid this is to learn how to gesture a body with basic skeletal construction before going into the full body poses you are doing. especially ones with clothing , i don't think you're at a technical level yet where you're ready to tackle cloth. basically you are skipping a few steps somewhere along the line and it's hurting your anatomy a lot.
you need to do more pics like your 1st one , but with more attention to detail and really learning how the body is constructed. you can also benefit a lot from doing things like studies of certain body parts on their own, like heads, faces, hands, etc.
i've done plenty of works with skeletons for a while in both life drawing and the 'drawing human figure in motion' class, i can't really be bothered to upload any of the others until probably tomorrow (i'm tired, and my scanner wakes up the whole house) they're predominantly gestural, however.
but you're right, i do tend to get caught up in the heat of the moment and forget to make the skeletal form first, which is kind of silly, because even way back when my drawings looked marginally worse, it was often the first step i would take (probably because it was the easiest and most forgiving)
and thank you, i'll make sure to utilize those resources in the future