I think I pushed the wrong button to reply, so I'll try again.
I started using CANVAS (now owned by acdsee.com) to draw 2D CAD drawings. This program is similar to CorelDraw and Adobe Illustrator. You can export your dxf drawings to your CAM program very easily.
Later on I used Trispectives, which became IronCad when bought up by a new company, to draw 3D CAD.
When my son was in the mechanical engineer program at his university, I got to use Artcam, which is excellent for more artistic designs. Nowadays you can buy pre-made 3D designs off the internet at places like vectorart3d.com