No matter what you make in SketchUp you will go through pretty much the same process. You draw the 2D shape first, push/pull it to the 3D size you want, remove any other details, and then make it a component. Every part of your drawing should be completed by making it a component. Once your parts are components they can be easily copied and moved around without accidentally changing the geometry.
Another benefit of making components is that all copies of components are updated. For example, lets say you drew a 2×4 that was 48″ long. You then copied this 2×4 30 times. If suddenly you remember that all of these 2x4s are supposed to be 50″ and not 48″ you can simply edit one to 50″ and every copy will update to 50″ as well.
