Thou shalt not use crappy tortillas
This is the tortilla which cometh from heaven, that man may eat thereof, and not die (John 6:50, kinda). But may great vengeance and furious anger strike down any taco shop that cuts corners by using crappy tortillas, especially given our country's great bounty of tortilla factories. Furthermore, should you serve corn tortillas, thou shall use two tortillas for every taco.
Thou shall be consistent with size
Thou might order one taco or two tacos or five tacos. Or 10 tacos or 20 tacos! But no matter the number, when returning to a trusted taco purveyor ye shall know no other taco size than what you received last time. If the taco size isn't consistent, then odds are it's not the only thing that's changing from visit to visit. No man should unknowingly order two tacos when three are needed.