- Make a new Camera View.
- Go to the View Properties of the Camera View, and select 'Section Box'
- To modify it, select the Section Box and then switch to a Plan View. The Section Box should still be selected, and you can modify the grips (you can modify these grips in many views).
Using this technique, you should be able to make some awesome cutaway views. These views can really help you to visualize and optimize your design.