Introduction to 3D Design - Autodesk AutoCAD 2013 Practical 3D Drafting and Design - page 32

Continuing set up, we create layers and other definitions. A winning command here
is ADCENTER , also known as Design Center ( Ctrl + 2 ) that allows for gathering all
layers, blocks, and other definitions from other drawings without opening them.
If we pretend to make some nice realistic images (rendering), we must be careful
with layers, knowing that the easiest way to assign materials is by layer.
Should we start from floor plans or elevations? Well, it depends on the project. We
can model from plans, but some parts may come from other views and then be posi-
tioned.
A final piece of advice is to keep several versions of your project. When an important
step is achieved, we must save a backup copy. If we change our mind about a step
or if the current file is corrupted, we minimize the losses.