Restaurant complaint etiquette: Bad food---> Ask to see a manager and complain, leave appropriate tip (20%). Bad service---> leave little or no tip. Long wai

Restaurant complaint etiquette: Bad food---> Ask to see a manager and complain, leave appropriate tip (20%). Bad service---> leave little or no tip. Long wait for food---->If server says nothing, leave little or no tip. If server apologizes and says they're having issues in the kitchen ask to talk to manager and leave an appropriate tip.