Jumping Up
The behaviour is usually learned while they are puppies. When a puppy is very young, we usually sit on the floor and allow our puppies to crawl all over us licking our face and ears. As they get bigger we laugh at the way they greet us with not just a wagging tail but often a full body waggle as we return home to them. It is practically impossible at this stage not to drop to the floor and engage in a mutual exchange of hugs and kisses. All this time we are training and rewarding our puppy for jumping up.
Our inconsistency perpetuates the problem.
Whilst you might not have a problem with greetings like this some of the time it becomes a different matter when you are all dressed up and either don't want to get covered in doghair or the remains of the last walk are still attached to your puppies paws. If you allow your dog to jump up sometimes and not others he will get confused and unfortunately telling your dog to get down or pushing him down will be misinterpreted by him as attention and may only add to the confusion. If your reprimand is severe enough, your dog may stop jumping at that moment but it doesn't solve the problem altogether; and it certainly is not a very nice thing to do. Even if your dog learns that jumping up on you is not a good idea, he will usually get away with jumping up on everyone else.
A better solution is providing your dog with an alternative method of greeting you and others. Teach your dog to sit and stay. He cannot sit and stay and jump up at the same time.
Practice is essential.
If your dog is excitedly jumping up when you return home from work and this only happens once a day, then he is only getting one practice session a day.
In order to perfect the proper greeting routine, your dog needs much more practice than that. You can speed up the training process by leaving through the back door and returning through the front door over and over again. When your friends come over, have them do the same. Each time, ask your dog to sit and stay before opening the door. At first his excitement will make it difficult for him to concentrate but after you've repeated this process 10 times, he will calm down and be able to concentrate. Remember to do everything in small steps and before asking your dog to sit and stay in a distracting and exciting situation, be sure he has a reliable sit and stay in normal, non-stressful situations.