Usually, when I have a model in for a session, I leave the drawings where they land, within the time constraints assigned to the pose.
Sometimes, the drawings are good.
Sometimes, I look and think “Did I draw that?”
And other times I think “Did I draw THAT?”
There are those rare occasions to look through the unfinished drawings. Oftentimes, fiddling with something beyond its time window can only make it worse.
And sometimes it makes it better.
And sometimes…
Tonight’s work:
Sex. Politics. Art. Cuisine. 
now u pointed it out, they are very detailed for what must have been a short session .
I generally take no longer than 20 minutes with a model on a pose. It took me roughly two hours in total to get the three drawings to where they are in the post.