Again, training and understanding your dog is rooted in knowing about Dog Body Language and Pack Behavior. 

You are tired and glad to be home. Boomer is jubilant to see you. Whether he claws your legs, collides into your chest, or knocks you sideways, Boomer welcomes you home. This reception may be acceptable to you. Unfortunately, relatives, friends, children, and delivery people may not care for Boomer's social graces, and may possibly be injured.

Puppy or adult, Boomer is trying to greet you appropriately, for a dog. He wants to lick your lips, either to show his respect for you as the leader or stimulate your gag reflex to produce the meal you've brought back from the hunt. Why else did you leave the den?

The reaction you demonstrate is appropriate, for a human. You might kneel down and lavish Boomer with petting, talking, and looking into his big, loving eyes. You might be annoyed, back away, push Boomer off, look at him, and tell him what you think of his manners. Either way, you have praised and trained Boomer to continue this behavior.

Simply put, what you do immediately after a dog does something encourages or discourages that particular behavior. Besides food or play, three strong rewards are: eye contact, touch, and a pleasant voice.

Both reactions described above contain these three rewards, even if you intended different results. Boomer will most likely repeat his welcome as you are inadvertently training him to do so.

Seeing the situation from a dog's view, try this solution.

As Boomer is rapidly closing the distance between you and is about to leap into his enthusiastic welcome, suddenly sidestep and turn your back to him. With your arms across your chest, empty or holding your packages, be still and do not look or speak to Boomer. Keep turning your back on him and watch him out of the corner of your eye until you see Boomer sit in bewilderment. When he sits, immediately look at him, praise him, and give him a short rub on his chest. If Boomer stands or jumps, turn your back on him and repeat the whole process.

Boomer will soon catch on that he can welcome you while his rump is on the floor. If your family and friends follow your example, Boomer will learn that by sitting he will gain the coos, petting, and loving attention from many people.

Oh, the power of a politely sitting dog!