Here are a couple of other options that won't necessarily require you to add temporary shapes for your "donut hole" features:
Creating the Shapes "From Scratch"
While you're digitizing the shape, draw your outer ring, right-click and select Finish Part.
When you draw the next part, the inner ring will create the donut "hole".
From Existing Polygons
Try using the Continue Feature tool. This will "open" the geometry and any shapes you begin to draw will be a new part.
Set the Trace tool active, then hit the O key to open the Trace Options dialog. Set the offset however you need to. Then click to start tracing at one of the feature vertices and go all the way around.
Edit: Another Thought
If you really need to keep the "inner" polygon as its own feature, the Buffer tool accepts negative distances, too. Just watch out for those rounded inner corners. The tool doesn't let you specify a mitered buffer, at least not yet.
- Josh Carlson
Kendall County GIS