It's been ~7-8 years, but I guess I probably figured out what trans-Munar injection velocity I needed and roughly what phase angle I wanted the Mun at (these are some basic astrodynamical calculations). You can determine velocity precisely from instruments and phase angle well enough from visuals that you pretty much guarantee a rendezvous.

Once you enter the Munar sphere of influence, just wait until periapsis and start killing velocity. You'll want a table prepared (somewhat conservatively, to give yourself room for fine-tuning) of what your velocity should be at a given altitude to make sure that you land at 0 m/s without using too much propellant, and remember to adjust the "sea level" altitudes for ground level before your radar altimeter kicks in. I guess the hard part is making sure you land on something flat, but you can impart some lateral impulse if necessary until you see a good landing spot below.

Getting back is similar, but the calculations are a bit simpler.