Recently I completed a course learning 2D and 3D Auto CAD, It was very interesting and I learned a lot I had never heard of this program before.
These are screenshots I took show some of my process when when creating a 3D Model,
Watering can from an exercise.
Half of a 2 part tool used to secure large glass walls and doors
referenced from real life as part of a work experience project.
Working in CAD is different to any other graphics program I've used before, I think modeling in, 3DS Max or Maya feel a bit like clay they way you push and pull on various parts and smooth them out but CAD is a bit like carving shapes into stone. I usually cut into the shape more than mold it.