Considering that my sketches are very willy-nilly, yes, I always end up doing a lot more when I ink. Like, when I sketch out a bunch of trees for example, they're just random scribbles on paper. When I ink them, though, I take care to make each canopy visible. In a wider sense, my series Biophilia is a major example of me drawing more than I was planning, since it was only supposed to be a one-shot, self contained story but evolved into a multi-chapter arc.
(I'm sorry but I just can't NOT acknowledge this: @joannekwan Oh my god they're going to the zoo!!!)