Currently this is the hardest thing for us, due to her tendency to back away and/or bark(or growl) at strangers approaching. It is progress, considering she is a former bolter at even a light breeze. This is for us to just move to the advanced class in our obedience class, it's currently holding us back.
While I don't ever intend to compete with her formally (I've thought about rally-o), I would really like to pass the lifetime membership test at this school which i believe has similar strict requirements.
She mostly knows the command. I can get her into a stand from either a sit or drop and also while heeling I can put her into a stand provided I move a little bit slowly while she obeys. *I* can feel her all over (teeth, ears etc) and gently push or throw toys/treats/do jumping jacks around her and she'll stay in position. I've been doing things like sweeping around her and touching her with odd objects. I'm hoping to set up old coke cans hanging from string from the garage roof for more distraction work (sit, heel, stand, drop...anything really. I am attempting to teach her to be mostly bomb proof to surprise movement and sound).
All of this goes out the window when a person (without a dog) is walking directly (or she perceives as directly) towards us outdoors. She'll hold it maybe 90% of the time with a drop, 70% with a sit and probably like 25% with a stand. I say outdoors because in the pet store we practice at she is more likely to hold her position and pretend like the person is not there. Same with the vet, where her stand is more 100%!. Which I reward heavily and she slowly relaxes when nothing "happens".
Currently at end of classes I ask either the trainer or the trainee trainers if they can do a couple of rounds of walking by her increasingly closely in various positions. They do similar in class but not as close. It's not something I can really practice outside of obedience since i think it'd be a bit of a liability.
So guess I am at a loss, to keep practising in our weekly class (when public holidays are not in the way...) and proofing with odd objects at home or if there is something else I can help her to "switch off" and not over think her fears.