Jumping is one of those behaviours that is incredibly easy to cure in a controlled environment....and then real life gets in the way.
The principle is simple. Never give a dog any attention unless all four feet are on the ground. That means don't look at, speak to or touch. Any attention - waving arms, telling off or shouting is still attention. Fold your arms, turn your back and ignore the dog completely until he is standing quietly. Then stroke and praise calmly. If there is any sign of a 'bounce' remove your hands immediately and turn your back again.
Be prepared for an extinction burst. It can happen with many behaviours that you are trying to extinguish but particularly with jumping up. You may notice that rather than give up, the dog just thinks that you are not getting the message and will try harder.This may take the form of jumping higher or using another unacceptable way of gaining your attention. Many people give up at this point and think that the method isn't working. Stick with it! This is "one final fling" before admitting defeat.
Dogs don't generalise very well, so you will need to practise the techniques with many people in varied locations until he understands that he must not jump up at anyone, anywhere, in any circumstances.
Leaping at VisitorsThe entrance to the house is a real "hot spot" for excitable, daft behaviour. It is far easier to keep your dog in in another room when people come to the front door. Allow your guests to walk into a dog free room before introducing your dog on a lead and under control. If he starts to behave badly, you can remove him and let him try again when he has gained a little composure.
Dogs learn by consequences of behaviour. Calm dignified behaviour brings attention. Loopy, daft behaviour means no attention and removal to another room. There is no need to treat the removal as a punishment, it should just be a chance to calm down for a minute before trying again.
Tethering to a RadiatorTie him on a six foot lead to a radiator or something similar and then walk towards him. The moment that he starts to "bounce", turn on your heel and march in the opposite direction.
Wait at the other end of the room until he is quiet and then walk towards him again. After a couple of attempts, you should be able to walk up to him while he remains calm. Stroke and treat him. Be prepared to remove attention if even one foot comes off the ground.
After a few days, when you know that he will remain calm when you approach him, you can "up the anti". Try waving your arms, skipping, talking in a high pitched voice, doing cartwheels, Marching the Dagenham girl pipers through etc.
Raise the level of excitement in easy stages. If he reacts, take it down a notch.
Make sure that other members of the family (and anyone else that you can rope in) practise this as well.
The same technique can be used if you have a safety gate across a doorway. If he tries to jump up just stand still and wait for him to put his feet on the ground or walk away.
Leaping around at people outside is more difficult to control. If you have friends that will co-operate, you can use the radiator technique but with you as the radiator.
You are bound to come across people who will fuss your dog as he jumps and will tell you that they don't mind. (They will when 30kg of doodle powered snog lands on their face!) I usually tell such people that someone smacked my dog in the face for jumping up and I am desperate to stop him. They are often eager to help after that and will aid with a bit of training.
It is worth working hard on a behaviour that is incompatible with jumping. It is impossible to sit and jump at the same time, so work on achieving a "sit"in any circumstances. Again, do this this by starting without distractions and then build up and generalise to anytime any place, anywhere.