Using DebuggerDisplay is both simple and really helps with troubleshooting. However, its automatic quoting of strings can sometime result in less than optimal tooltip display.
For example, if you have Key and Value field with "Foo" and "Bar" as their respective content, you might end up with the following attribute:
DebuggerDisplay("{Key}: {Value}");
This will result in "Foo": "Bar"
tooltip text. While not a big deal, these excessive quotes can be a bit of annoyance. Fortunately, you can tell DebuggerDisplay to stops its auto-quoting:
DebuggerDisplay("{Key,nq}: {Value,nq}");
This will result in much nicer-looking Foo: Bar
output.