No requirements. No conventions. We all as writers have our opinions on the right way of course, and some of us are more vocal than others on that front, but there isn't a universal way to write a Mandalorian. Just as there is no universal definition or way to be one. That is honestly the beauty. I used to write this guy as the head of Clan Mereel. Know what's awesome though? If you wanted to, you could use the name and beyond politeness there is nothing stopping you.
Do you. Write your story and character. Go freaking nuts and see what happens. You might wind up Manda'lor. You might blow up a planet, or throw an asteroid into one, or become Dark Lord of the Sith. Mandalorians do cray-cray things.