I have had Shelby for about 4 months now and she is the same way (she is 1.5 yrs). What I have been trying to do with Shelby is inviting some dog friendly people over that are willing to help me with the training. They let me know when they are coming and I put Shelby on a leash. I leave the front door unlocked (since I live alone, I dont' have anyone to help) and put Shel on a sit/stay or down/stay a couple feet from the door when I see them coming to the door. They ring the bell and I say "come in". If Shelby stays as she is suppose to , I instruct the person to say hello and pet her, however, if she gets up, I immediatly instruct the person to stop petting her and I put her back on a sit/ stay. I have done this a couple times and it seems to be working fairly well. In the mean time, when I have someone coming over that I don't trust to assist with training, or don't want walking in my front door (delivary ect...), I try to put Shelby away in her room with her crate until that person leaves or I have the abiltiy to put her on a leash to introduce her and settle her down. It seems to be working for her. She will always be excitable, that is just her, I am just tring to redirect that energy. I dont know if this would work for other dogs, but it is working for her. I don't even usually have to use treats for rewards, the attention, when she is being good, seems to be reward enough for her. Good luck.

than it is for Darby to understand what behavior is expected of him:p .