Summarize this article in one sentence.
The simple 'sit' command can be useful in many different situations. Most importantly, it is a great distraction technique for redirecting your dog's attention from an undesirable behavior, such as jumping up. When your dog jumps up on you, turn your back to them while keeping them in your peripheral vision. Ask her to sit and immediately praise her when she does so.  If your dog is too excited to notice that you are asking her to sit, ignore her excited behavior until she calms down, and then repeat the command. Again, as soon as she follows your command, give her lots of praise or a special treat to let her know this is the behavior that gets rewarded, not jumping. With this simple command, the goal is to redirect your dog's jumping behavior with a task that should be easy to perform and then rewarded well. Your dog will soon figure out which greetings get her your full attention and which don't. If your dog doesn't know the sit command yet, start teaching her the command along and then try this method. Some dogs exude such extreme excitement when greeting someone that it may be difficult and time consuming to wait for them to calm down for a redirecting sit command. If this sounds like your dog, she may be more inclined to grab a toy and shake it or hold it instead. Keep a special toy by your front door to throw for your dog or give to her when you come home. This will redirect her energy into playing with the toy as opposed to jumping on you or your guests. The key to keeping your dog calm, and therefore exhibit calm behavior, is to also participate in only calm behavior when you come home. Try not to use a high-pitched or loud voice when talking to her. This includes shouting at her when she starts jumping up. This type of vocal tone could encourage more excitement and jumping.  Instead of using physical punishment to discourage bad behavior, teach your dog what behaviors get them the most rewards from you. You will have to repeat the actions of her training multiple times before she will get it. Don't get frustrated or upset because this will make her worse. Keep at it and she will eventually catch on

Summary:
Redirect with a sit command. Use a special toy. Stay calm.