16 dining etiquette rules every professional should know

"You are there for business, not for the leftovers," Pachter writes. "Doggie bags are okay for family dinners but not during professional occasions."

This one seems like an obvious no-no, but it still happens.

"Don't whip out the dental floss or use your toothpick or pinky nail to remove the stuck piece of broccoli while you're at the table," Randall writes.

And "don't swoosh your finger around your mouth to get the leftover chunks. (That's super gross!)"

The napkin should only be used for blotting the sides of your mouth. If you need to blow your nose, Pachter advises excusing yourself to the bathroom.

"You are not the waiter," Pachter writes. "Let the wait staff do their jobs."

"Place your knife and fork in the rest position (knife near the top of plate, fork across middle of plate) to let the waiter know you are resting," Pachter writes.

"Use the finished position (fork below the knife, diagonally across the plate) to indicate that you have finished eating."

Don't use it for texting, and definitely don't use it for Instagramming.

"No photos of your Nicoise salad are necessary," Randall writes.

Randall says this is a big faux pas.

Instead, she recommends: "Using your left index finger and thumb, quickly remove the morsel and place it under a lettuce leaf. Wipe your fingers on your napkin."

Of course, Randall caveats, you shouldn't do this if you're in the middle of a conversation. In that case, excuse yourself to fix the situation in the restroom.

Pachter says you should never use your knife to cut your rolls at a business dinner. "Break your roll in half and tear off one piece at a time, and butter the piece as you are ready to eat it."

"Do not complain or criticize the service or food," Pachter writes. "Your complaints will appear negative, and it is an insult to your host to criticize."

The mnemonic BMW here stands for "bread, meal, and water," so remember that "your bread-and-butter plate is on the left, the meal is in the middle, and your water glass is on the right," Pachter writes.

Each course should have its own utensils, and all of them may already be in front of you or will be placed in front of you as the dishes are served.

In the case that all of the utensils are there at the beginning of the meal, a good general rule is to start with utensils on the outside and work your way in as the meal goes on.

Here's Pachter's guide to using the proper utensils:

"The largest fork is generally the entrée fork. The salad fork is smaller. The largest spoon is usually the soup spoon.

"If you are having a fish course, you may see the fish knife and fork as part of the place setting.

"The utensils above the plate are the dessert fork and spoon, although these may sometimes be placed on either side of the plate or brought in with the dessert."

If your guest orders an appetizer or dessert, you should follow suit. "You don't want to make your guest feel uncomfortable by eating a course alone," Pachter writes.

Randall suggests that you keep the napkin folded in half, unfold it below the table, and then place it on your lap.

It's OK to hold open a door for your guest, but Pachter says you shouldn't pull someone's chair out for them, regardless of gender. In a business setting, you should leave those gendered social rules behind.

This means picking an appropriate restaurant and making reservations ahead of time, which is especially important if you're having a business lunch or dinner at a time that can be busy. The last thing you want is to be told there isn't a table available for you and your guest(s).

Once you're seated, "you need to take charge of the logistics of the meal," Pachter writes. Direct your guests to their seats and recommend menu items in various price ranges.