Foghorn's point about knowing the area is important, and is a benefit of Bournemouth, where we have a CAAFEU (CAA Flight Examiners' Unit) so we fly all tests from here. When I was given a diversion it was to a place I had done a diversion to before, and had flown over on another occasion, with the prosaic name of Puddletown.
Add my point about DR practice to his about diversions - good mental DR will help your diversion leg no end.