1) fully inspect before signing off, paying, accepting.
2) be reasonable. Tesla will say just sign, they can fix everything, but you have to judge what is practical and material. For example, I accepted a car with immaterial paint flaws and slight panel mis-alignment. But rejected a car that had a ding in the A pillar and wrinkles in the seats. No way to fix those 2 things. My line in the sand was this: nothing that requires them to send to a body shop.
3) if you find issues you are deeply concerned about, ask them to fix before you accept car.
4) be nice. They will work much harder to accommodate you.
5) if you accept car with “due bill” of items for Tesla to fix, get that in writing, don’t settle for email later.