Restaurant consultant reveals what customers should never do when dining out

When it comes to dining out, there are some unwritten rules of etiquette between server and customer that are important to know.

Salar Sheik, a Los Angeles-based restaurant consultant and founder of Savory Hospitality, told Fox News Digital that the rudest thing a customer can do is "one-timing" a server.

That's when a customer asks for something like a glass of water, for example — but when the server returns, the customer then asks for something else, Sheik said.

RESTAURANT TIPPING ETIQUETTE...