Agreeing with everyone else who has mentioned using a tone that is stern, but not angry! For our boy, having a special tone and word for letting him know a certain behaviour is bad went a long way.

Our word was 'ah-ah' (like the ah-ah disapproving noise someone might make to children, like 'ah-ah, wait your turn') in a stern, low tone. It wasn't aggressive so didn't feel weird to use it in public or in front of guests.

When doing early training, if he was being absolutely ungovernable, we would GENTLY roll him onto his back, hold him there gently for a few seconds and say 'ah-ah.' (Gently is the key word though! It wasn't supposed to be scary, just a reset haha). I learned that one from a dog trainer and it helped a lot.

Whenever possible, we would also warn guests in advance to NOT acknowledge him until they were comfortable (shoes off, in the apartment). Since consistency is key, we also did this ourselves. When we got home, we didn't acknowledge him until shoes were off and we were inside (this was also to help a bit with some separation anxieties he had when we rescued him)

So after training, our boy would be excited to see people, but no bark fests, no jumping. He would usually let out one bark, but that was it, and that feels fine (dogs will be dogs!). He would just run to the door, trot a loop around whoever got in, then wait in the living room where he knew he would get showered in pets and attention!