It depends! If I'm going for a complex illustration, it takes me around an hour for planning it. I use Magic Poser to figure out the angle and character position I want. Then the sketching is usually done rather quickly. Between 15 minutes to half an hour depending on my mood and how thoroughly I have planned the scene. Inking takes me around 4 to 5 hours if it is complex. I try to not work more than 10 hours on a piece since I'm impatient. If we look at the sinlge character drawings that are not planned through I can finish a piece in an hour. These usually have coloured pencil lines that I photoshop out. :)