My thumbs are basically my pencils! I ink directly on top of them (thanks digital media!!) so while my thumbs vary in quality and definition, I try to make sure I always give myself enough to go off of no matter what, just in case I happen to spend a lot of time away from them and can't remember what it was I was thinking.
This usually means I try to ALWAYS make sure the expressions are very obvious, as well as anything else I think is important. I tend to spend this time really figuring out the essence of the backgrounds as well, because trying to come up with it later is really ... hard for me. If I am too loose during this stage for the background, usually it means that there won't be a very good background during inks, or I'll drop it entirely. In worst case scenarios where I still VERY MUCH need a background but didn't give myself a good enough one in thumbs, I have to rethumb the panel, and that just takes time away as well as ruin my Inking Groove.
This is also the stage where I try to decide on a lot of the lettering, IE placement and beats. I'm a very visual person, so it's fairly difficult for me to thumb out a scene without text directly involved.
Hope you're enjoying the sneakpeak!! LOVE Y'ALL!!!