stand when rocking out, sit while learning
About 50.99% of the time it's sitting, classically. I just use anything as a foot stool, a pile of books or anything really. But I also play a lot standing up. I like both.
It's funny to me how the older dudes in general are more partial to sitting. Too many years of standing while rocking out! This is why I'll be playing in my 90's. This is why BB King is still playing in his 110's!