Are you going to override ToString? You do this from time to time, definitely.
You begin typing format string and immediately see ReSharper coming to rescue in an absolutely non-invasive way. First the light bulb will appear.
Second, you hit Alt-Enter to see the list of available context actions. Only one is available here, but it is exactly the one we need.
Accept it with Enter and you can start typing arguments.
Note: Some or all of the features mentioned in this article may be available only in latest EAP versions of ReSharper.