I have a handful of different edits that I do. The first is what I call the triage edit, where I figure out how the story needs to be fixed, if I need to get rid of a character or add a few (which hasn't happened yet), remove a plotline or build up a character.
The second and third edits are the hardest for me--emotion and description. Some of these books have languished for months on these two edits.
Since "too little description" is one of the standing complaints from my readers, I made a description edit an official part of my editing program.
I don't do description easily. I'm not sure why. I tried a description exercise a few months ago and got almost a full page into it before I realized I hadn't used a single adjective. No shapes, no colors, no sounds or smells. I can get through several pages without a single piece of the "setting" making itself seen.
Actions, sure. Here or there I use action as a dialogue tag, or my characters interact with their environment. Expressions, the way people hold their hands or a turn of the head might be all the description you get in the first draft.
I know that bugs a lot of people, although I personally have no problem with it. However, since I'm not writing just for myself I must make allowances.
I also don't like physical details. If my writing is going to have hair color, eye color, skin color, it had better have a reason for being there. So my characters live in a colorless vacuum which drives my writing group crazy. I have a good idea of the basic general types in whichever world I'm playing with and if there are physical details they're likely to be in contrast to someone who looks different.
Again, this is first draft stuff. The description edit is the second edit I do, and I try to put some kind of description in each paragraph. Sometimes I get so caught up in reading that I forget and have to go over the same passage five or six times before I get enough description in there.
Other times it doesn't seem to matter. If the story is flowing fast without it, I might let it go. It's when I start getting comments like "too much description" that I start screaming in frustration. :)