Um, well, what has your bird already learned? Do they do flight recall? Because until they come when called that's going to be a tough trick to teach! You might try teaching them to fetch a dollar sitting on a counter a few feet away from them and move from there. But flying up to a stranger, grabbing a dollar from them, and returning it to you would be considered a fairly high level trick IMO.
Well, once the bird is trained to fetch, it's the object, not the person holding it.
You train him to seek out the object and bring it back to you.
It's a fairly simple trick. IF he's already recalled and trained to fetch objects.
If he's not, then you are at square one, and you need to first break it down and get him to identify the object and pick it up.
Then you need to get him to fetch it, and bring it back to you.
Then you work with him fetching it from another trainer.
Then another trainer in the crowd.
Then switch the bill off with several people in the crowd.
Reinforce that for about a week, and he's usually got it.
This is assuming the bird is already conditioned to perform around strangers.
If the bird was previously trained to fetch using a target stick, then a target stick is used to identify the object you want him to fetch at first... but that can end up being a crutch cuz you're not going to have that stick during the performance, right? So, I would do object identification...
Personally, I didn't use a target stick. Sally learned this one by object identification using the bill. Only Sally was trained to "pay the check." Instead of bringing ME the bill, she took the bill out of my wallet and gave it to a stranger. Also a simple fetch trick... only she wasn't a performing bird, she just went out everywhere with me. So the bird paid...
In Sally's case, I pull out my wallet, and secretly cue the bird by sticking one corner of the bill I want her to take out above the others. Then set the wallet down on the table. She opens the wallet, pulls out the bill, and then gives it to the waitress...
