I wouldn't get fixated on a particular crater, not least as they will be on the night side sometimes (and therefore ineligible for the Vagabond bonus). When I was testing it, I would just approach the day side close to the terminator where the shadows are clear, which shows up the craters well, and pick whichever I had a good angle for. If there's a really large crater, e.g. the rayed craters many moons have, then I would preferentially aim for that before I reached orbital cruise but anything you see from orbital cruise will be large enough to qualify.