AutoCAD 3D Basics Tutorial Part 1 - Thickness + 3D Faces
This video demonstrates 2 of the most basic modelling methods - 'thickness' and '3d facing'. Basic 2D AutoCAD proficiency is required if you want to try it yourself. No additional files are needed.
These 2 simple methods should not be disregarded, a model can be a complete hybrid of methods, 3D Studio max which is the end goal does not care how your model was made. 3d facing is super editable and once you get the hang of it it is controllable and most importantly very accurate.