Now I'm going to go into a little more detail on how to flesh out those scenes. We all do it differently. My techniques might make you laugh.
As I edit I look at several things to be sure it flows. I ask myself does the dialogue move along nicely or does it seem choppy? Does it make sense as I read it or did I leave something out? Is there enough detail? Can you tell where they are? do I need to add more description? What they are doing? Is it nothing but talking heads or do I show them in action as they talk? Is it consistent?' You sure don't want them standing one minute then a couple paragraphs later have them stand up.
As I work my way through the my work in progress these type of questions float in the back of my mind. I have found if I rush it by trying to do my edits all in one run I make myself crazy and it takes too long. So I layer it. I'll go through and fix what really jumps out at me. Then let it sit for a few days then go back through it again. I know it sounds like a lot of work but it works for me.
That is what every writer needs to do. Find the method that works for them. I learned the rules we're taught don't always work for everyone. Do what works for you.