What programs do you use? I used to use Orcad for my schematics but too pricey for PCB routing too so I use Eagle Cadsoft for both now.
A guy on this board also told me about Google Sketchup. It's great for expressing a 3D concept of say a finished product or just an idea you may have.
Sometimes we must do mechanical drawings for even the small things like boxes and face plates. I found a great one for free by Siemens and I have used it to make money. It is very large, about 238 MBs but it can make your mechanical drawings where they will load up in AutoCad. You can do print outs in JPGs as well. It is very in depth. The name of it is "Solid Edge".
I use PTC Pro/Desktop 8 because this is the application they taught and gave us at school. It is a bit tricky to learn at first, but does really work well.