Let your grey card be your standard reference, for film exposure, film . developing, developing prints, and final finished work.
In other words, your personal Zone System, with additional cards, keyed to one main card, over time.
If you like low or high key work, you can calibrate your kit to give steady results, or work from a middle key, it’s nothing special, just steadyness in your processes working toward one result..
Meters can be adjusted for one common result and, in my opinion, is the most difficult chiore but will make your results so much better over a wide range of negatives.