My puppy isn't 7 months old yet.
I have taken him to classes nearly every week since he completed his vaccinations and we had a 1-1 prior to that at home with the trainer.
I have taught him a default sit on seeing people or pets when out and about, middle, hand touch, look at me. I have always rewarded calm when he sees people approaching, and voluntary eye contact with me. If need be I do encourage his focus onto me with things like middle and hand touch which is what the trainer taught us to do, I did not realise it was wrong for me to be "distracting" him, as advised above by the comment that I am distracting not training him by doing this. I keep him on a lead, or a long line (held or trailing) in what are mostly empty fields once we get there - he is not bounding over and jumping at strangers, he is pretty good at recalling atm but I cannot predict when he will have a bad hormone day so, longline. I can't follow advice on here to "walk in different areas until he's trained" and always avoid anywhere he is "too close to his triggers" because I do have to walk out my front door and down my own street to get anywhere.
My frustration expressed above was that people come up and pet him, and he then doesn't have the self control to stay sitting nicely once someone has approached and started petting him, he is on his feet wagging his whole little body and will often manage to land a muddy paw on clean trouser legs, even with a hand on harness assuming I've moved fast enough. Some people are then upset. Others will say it's fine, my dogs do it all the time, or oh I was muddy already, but either way it encourages him to do it again.
I find it hard to tell people who approach without asking or waiting for permission to keep back, without feeling it's rude or discourteous and abrupt and could offend people.
There is a massive amount of judgment on this thread but I do still think that the widespread attitude that cute puppies are public property for petting, doesn't help and undermines owners efforts to train. I stand by that view and the general point I was trying to make. Though obviously for my personal situation I take the criticism on board that I have been failing at training my puppy and am showing no respect to the public (and have had a proper sob about it if that affords reassurance it has been taken to heart).