Jay Bates, the renowned sketchup teacher, will teach you how to generate the model of a coat rack with sketchup through this exclusive sketchup youtube video. Sketchup can simplify the process for woodworking and carpentry construction. By watching this sketchup tutorial video one can learn how to deal with spaces for invisible & small dimensions.
Mr. Jay used the following sketchup shortcuts for accelerating the modeling process.
Ctrl = adds a copy command to the move and rotate commands
Q = rotate
R = rectangle
T = tape measure
D = dimension (this is a custom keyboard shortcut I set and is not included by default)
M = move
Space Bar = selection command
Triple Click = when triple clicking a piece of model space geometry it selects everything in model space that is connected to that item
Double Click On Component = enters component edit mode
G = Activates selected model space geometry into a component