One of the most useful pairs of commands in MonoDevelop is Show Next Result and Show Previous Result. These commands move through items in the most recently active navigation list. Right after building, they will cycle though the build errors and warnings; after searching, they cycle through the search results; after running unit tests, they cycle though the test failures, and so on.
The commands can be found in the Search menu as Show Previous and Show Next, and the names change to indicate which type of result is active. The keyboard shortcuts on Windows and Linux are F4 to move to the next result, and Shift-F4 to move to the previous result. On Mac, they’re Command-= and Command-+ respectively.