flowermug, what worked for my parents was the approach you'd expect from a very experienced teacher or an old-fashioned nanny:
gaining respect by building up an image of yourself as fair but firm- doesn't happen overnight, but once you've got there it's an invaluable tool
being consistent about rules and punishment
thinking ahead and pre-empting dangerous situations- a situation that never arises is one where you don't have to punish
staying very calm when things blow up
not giving in but equally not losing your temper
not getting overly emotional
never letting them see that you are afraid of losing control
firmly ensuring that everybody is safe (small children can be lifted out of harm's way)
being sparing in actual punishments but not backing down once you have decided to go down that route
having high standards yourself in matters of manners and self-control
working on a good relationship when things are going well, so you become the person they don't want to let down
accepting that you may have to deal with a situation more than once- it's the long haul that does it!
They weren't just dealing with easy-going compliant children: I was very rebellious as a small child and my younger brother had violent meltdowns (probably result of attachment disorder/PTSD). They spent plenty of time dealing with screaming non-compliant children. But they got there with (on the whole) minimum disruption to other people, it worked.