Well it's really difficult to say.
One DC has sensory issues and other stuff, and struggled a lot with emotions and anger, from 2 onwards it was very hard parenting them, we had boundaries and when told off or asked to go calm down, would kick spindles out of the stairs and doors, the melt downs could last an hour or so. there was no point at all with trying to engage once in that state, so it was always a long time after that it was then safe to sit down and talk about the reaction and the original incident, then consequences would be laid out, unfortunately sometimes this could start another rage. But from 13 onwards (18 now) is loverly respectful and thoughtful. it was a very difficult time with no support and a local council not willing to do assessments.
The other DC in comparison was easier but also struggled with emotions and was unreachable once upset. their difficult period was between 7 and 10.
I made lots of mistakes, shouted, lost my temper, and felt like a terrible, useless mother for many years.
But both are thoughtful and respectful of us as parents and people and friends around them, they have amazing sense's of humour, and chat and talk openly to DH and me.
I suppose it could have been that we always talked with them calmly after the issues, we listened to how the felt, we tried to help them to avoid getting like that in the first place. We followed through with consequences but tried not to do knee jerk consequences that would be hard or stupid to actually do. We also apologised to them if we had not managed to behave as we should.
I really don't know, how or why they are lovely teens now. I'm sure someone else could have done the same as me and DH and still have problems. I just feel lucky that's all.