I have a 3.5 month old that is very friendly but I don't like strangers touching her either. I got her a harness with patches that says DO NOT PET. That way if I come off as rude the warning was right there in plain sight. If they don't like that then tuff!
This is too bad.
This thread was started because unfortunately there are dogs that are not courageous and aloof, but scared poopless of new and different situations because of temperament issues.
If you have a well balanced, happy puppy, the best thing you can do is to let her interact with many people. Heaven forbid that something would happen where she was not with you, you would want her to know how to behave appropriately around people.
Also, while that vest can be great, you have kids who can't read, people who can't read, language differences, etc. So they are not a cure all.
As far as the question, I have learned over time that you have a very short amount of time to convey your message, and that the way you do it will have an impact on how successful you are.
1. You need to be aware of your surroundings all the time when you are out with your fearful dog. This means if you are having a conversation with someone, you are glancing at them, and making the more constant eye contact with your dog and the area around them. You are scanning your environment for people and things to approach.
2. You need to understand what your dogs triggers are - is it motion? If you are on a path and someone runs past, will your dog lunge? Or is it people approaching that freaks them out? Or both, all and more.
3. What are your dogs' calming signals. Can you recognize when they are uncomfortable.
Those kind of things help you to control your environment better.
Then as far as people...
1. Understand as much as you want to think it, you may not be able to control other people. This may be okay in a quieter environment, with a few random strangers, but will not be okay at a festival, soccer game, pet store, etc. So you have to know you and know your dog and figure out what you both can deal with.
2. Humor and kindness and a smile go a long way toward stopping people. Since 1992 I have been warning people off a dog in one way or another. Fact and logic are things that I like, but have found that not many people respond to! A barking, lunging dog aren't even enough to stop them! So put forth your most charming self. This is to help your dog, so suck it up and put the sour patch attitude away for a time that your dog is not involved.
3. Because you have scanned your environment, you have much longer to warn people off. Use this to set yourself physically.
4. Think of a great, firm but fair teacher you have had. Their way of handling people, their ability to make eye contact and stand tall - while I don't agree with a lot of what Cesar Millan does, what he tells you to do to your dog - do to other people - firm, tall, and someone who knows what they are doing. People respond to this body language.
5. Body block - step in front of your dog. Do it before the person is there - 3 feet at the least.
6. Use whatever canned message you have found to work. I use "she's shy" or "she's scared" and that works. People understand what it's like to be scared, more than they understand "she wants to rip your face off" because they can relate to that. There still may be people who will downplay it, but you are set up in front of your dog.
7. If they still come at - which there will be someone who will - you have set yourself up in your environment - make sure in that set up you have given yourself an escape route. I will step in toward the person, making them back up and then swing around and exit.
8. I also use a 4 foot leash so there isn't a lot of play on the lead for my dog to move forward on their own and wrap it shorter as needed - for example as I make the move into that person's space, I have the dog held back with my other arm backwards the distance of my arm - so the lunge would only get them to me, not farther.
Last part - what you are doing with your dog.
1. I make sure I am doing all this in an environment they can handle. I have not always done that well - wanting to expose them more than they have wanted to be or were ready for. Now I may go too far the other way in terms of being slow, but it still seems to work out well in the end. So there is a part of that that is desensitization.
2. I am giving the dog a lot of feedback, verbally, with my body position and hands. Even if someone is talking to me, if my dog does something well - ignores something or makes eye contact with someone, whatever, I will interrupt to tell my dog nice job! using that high and happy voice. If I see they are getting tense, I can tell them easy with that lower, soothing voice. I can put hands on my dog to let them know I am with them, and also, again, use my body to stop them from being able to see something that we need to move away from. But I mark positives a ton so that I am constantly shaping the behavior that I desire from them. It is like when you are learning a new skill - imagine something you've never done and are anxious about - skydiving maybe. And the instructor doesn't say anything while you are putting on your equipment and getting on the plane...that's a lot more difficult for you than if they are giving you feedback.
3. IF your dog will take treats from a stranger (I have had dogs that will not) and it helps, use them. It may just be that they see a person and you give them treats - it all depends on how you are doing the desensitization and work with them. Do not let a stranger tell your dog to sit - tell the person firmly that them approaching you is the behavior you want, nothing else.
4. Look like an idiot for your dog. Be willing to work with them in a way that may look stupid but if it works for your dog, go ahead and do it. For my one dog, clapping and saying Hercules! Hercules! was her reward. I think what it did was take any residual anxiety I might have about a situation and rid it from me - thereby allowing her to relax and enjoy her accomplishments.
5. Consider finding a handler/dog mentor team. An upbeat, smart person and a confident, well balanced dog can show us a lot and help your dog to have behaviors to model.
Managing these dogs well means that when you are out, you are out for them, not for you.