Jumping up is a social greeting and attention-seeking behavior. It means your dog is friendly (in most cases - although it can also be charged with a bit of frantic or anxious energy which will require very patient and positive-based training).
I use a couple methods to work on this, depending on the environment and the dog. I find that the old "turn your back and ignore" doesn't tend to work very well. It does help to practice your dog's sit so that becomes an easy thing for your dog to do instead of jumping even if excited.
Method 1: Using a door: Crack the door open with your dog on the other side. Ask your dog to sit. If your dog sits (or is otherwise calm), slowly enter. If your dog jumps, say "eh eh" or "no" and leave and close the door. Repeat. You can also exit a door anytime your dog jumps on you once you are inside. Using a tether/leash: Approach your dog, if your dog sits, feed a treat or otherwise greet, but if your dog jumps, say "eh eh" or "no" and leave the area. Repeat.
Method 2: If your dog is free (no leash etc,) and you have no reason to suspect any anxiety: Say "eh eh" and carefully, but forcefully, walk forward into your dog when she jumps on you. Then ask for and reward sitting.
With both of these methods it helps to practice being silly or doing things that may tempt jumping up (such as dancing around, putting your arms up, sitting or bending down, holding something above your dog's head) and work with the above methods to show your dog not to jump up even during these distractions.