The first rules of table etiquette apply right when you are sitting down to the table. Remove any electronic devices or turn them off before sitting down. Right after you sit down, put your napkin on your lap. If you are a guest, wait for everyone to be served and for the host to take the first bite before starting on your own meal. If you are presiding at your own table, you can start to eat and guests will follow.
Etiquette guidelines recommend how to use the utensils in front of you. The basic rule of thumb is to start from the outside and work in. If there are two forks on your left, use the outermost fork for the appetizer or salad, then the inner fork for the entrée. When you are finished with a utensil, set it on the plate to be cleared. Place the utensils across the middle so they won't fall off when the plate is lifted up. Put soup spoons on the soup bowl's saucer when finished.
Posture is an important part of table etiquette. Never eat with your elbows on the table and don't hunch over your plate. Instead, keep your wrists or forearms resting lightly on the table's edge and bring the food up to your mouth as you sit straight and tall. Your feet should be placed squarely on the floor, not stretched out or wrapped around the chair legs.
How you eat is really the basis of all etiquette guidelines. Load up the fork or spoon about 2/3 full so you don't put too much in your mouth. Chew with your mouth closed and don't smack or slurp. Chew and swallow before taking another bite and take it slow. If you discover something in the bite that is inedible, such as an olive pit, discreetly remove it with your fork and put it back on your plate