It can be difficult to decide what to order at a restaurant, but figuring out the tip can be confusing and frustrating.

"Tipping is the way you have, that opportunity to say thank you," says Marc Sauter, sommelier and co-owner of Zinc Brasserie in Virginia Beach.

If you’ve never worked in the food and beverage industry, you may not be aware of tipping's signifigance.

Etiquette expert Susanna Theo explains who and how much you should tip.

"Servers should always be tipped 15 to 20 percent. Coat check is usually a dollar for the first coat and 50 cents thereafter. A valet should be maybe $1 or $2.  At the bar, the rule that they have out there is usually a dollar to two and then 50 cents thereafter," she recommends.

If wine is part of your check, there’s typically a 15-20 percent tip for the wine steward.

Theo stresses that there is never a time you shouldn’t tip.

Sauter agrees, saying there is a better solution to bad service.

"I think to leave a really bad tip would be to leave three to five percent.  It's so much better than leaving zero. The server or bartender generally has a bar back, a buser, expediter or someone they have to tip out to. To leave them zero, they kind of wonder did they just forget?," he says.

Remember, several people typically are splitting the tips.

If you receive exceptional service, tipping above the norm is up to you.

Whatever you decide, the percentage should be based on the before-tax total, not the total after tax is added.

"You should be accommodated. You should be well taken care of," notes Sauter. "And when someone's gonna go that extra mile and really go over the top and really take good care of you."