I'm doing a lot more work in the final inking of a piece than I used to do - mostly because I already know what I'm going to be doing on certain textures, so I don't really have to render them in pencil. So for a drawing, I need to get the composition right, and certain details (such as facial features) that I don't want to improvise in ink. But all the rest can be done on the fly.
The best recent example is this piece I just did for the excellent (EXCELLENT, should be a novel) story "Mudlarks", by Kat Otis, for Orson Scott Card's Intergalactic Medicine Show magazine. The pencil art is below. Click through on the link underneath to see the finished art to compare. (The preview is free - but this story alone is worth the $2.50 price to read the whole magazine.)
(Also - clicking on the magazine illo will give you a bigger pop-out window so you can better compare the art.)