Oh, I do the parts in sessions. And leave things undone for the time being if I dont want to model them at that instance. And I know the little work will be rewarding, but I must confess I have no goal or major purpose yet. So I model and just watch the falcon come together. Besides it is more fun for me to practice at rendering when I have a facinating project to show for, and not some simple set of primitives. Although things can be made less detailed than the falcon project. Fun Fun Fun !!!