a bunch of things that I know are going to sound really corny (which honestly I think is half the cultural problem - the idea that non-coercive parenting is touchy-feely, ineffectual or just kind of cringe - but that could be a whole other post)
the main thing was that they always explained things to me. if I wanted something I couldn't have, they explained why (from 'we can't afford that', 'it's bad for you', 'it's dangerous', all the way up to 'it's made by a big company that treats its workers badly, and we don't want to give them money'). If I threw a tantrum, they either waited it out until I got tired and bored or they redirected what we were doing ('we have to be patient and wait in line. if we don't wait in line, we can't go into the theatre. we can't wait in line if you scream and upset people. okay then, we're going home.')
beyond that, they always spoke to me like a full person. they asked my opinion on things and took it seriously, and asked me why as much as I asked them. apparently I had a phase as a toddler where I always wanted to be the first one on the swings / down the slide, and would throw almighty fits about it, until my mum took me aside one day and said 'why do you want to be first? are you worried the slide will get used up?' I laughed like it was the funniest thing I'd ever heard, and never kicked up a fuss about taking turns after that.
on the granular level, they focused on positives over negatives. My mum would draw little good behaviour charts for me, featuring e.g. me walking a long winding path through the woods with my soft toys. the path would be made up of, say, 30 stones, and every day that I was well behaved I'd earn a sticker on one of them. when I reached the end of the path, I got to pick a treat. something like a new plastic animal for my collection, or a day trip to the aquarium.
I do remember them sitting me down once and asking me to come up with what I thought would be an appropriate punishment if I ever did something really bad. I think my first suggestion was something like 'no TV', which was a real nice try because we didn't have a TV at the time. I don't remember what I finally decided on, it might have been 'no dessert for a week'. We wrote it down together and I signed my name, and they sealed it in an important looking envelope which they put in my dad's filing cabinet (for important documents). This would be unsealed if I ever did something Really Bad. the eventuality never came up, but the act of participating in the exercise kept me mostly on the straight and narrow. It's funny, the conceptual punishment itself wasn't even that bad. It was the seriousnes of the adult commitment I'd made to Behaving Well that did the trick.
When I DID do the standard naughty stuff, my parents would just sit me down and explain to me seriously why it was wrong and what impact it had caused for other people. They'd ask what motivated me, and why I acted on those feelings in that specific way. They would, of course, tell me they were disappointed. If necessary, they would tell me how things would have to change as a result of what I'd done. They were always, always open to hearing out my side of the story, and always, always took my feelings seriously even if they disapproved of my behaviour. they would ask if I was ready to say sorry and get a hug. if I wasn't ready, if I was still upset or angry, they would give me space in my room and ask me to come find them when I wanted to make up. and I always did, because I always knew they would accept it.
