My parents were terrible, so I could tell you more about what not to do. Certainly don’t make your problems their problems. I was always aware of their stress, money worries and unhappiness and I could never feel relaxed at home. Being in a warm, loving, engaged family setting is important. Would have been nice to feel my parents loved each other rather than loathed each other.
Consistency is a big one. My mother expected us to do well but then was jealous of it so didn’t support us either. It’s very confusing.
With my kids I encouraged them to do things themselves from an early (but age appropriate) age, like speak to adults, pay in shops, go on the bus, learn to cook, and generally look after yourself. I think being able to manage things and be competent at stuff while being supported and given advice is really important to build resilience. This doesn’t mean being abandoned and left to get on with it though.
I took them to classes to learn to swim, play tennis, football, karate etc. It meant they could always give someone a game or join in or having something in common with people so that was worth the investment.
I taught them to be kind but not always put others first. My parents were so big on not being selfish and centring other people that I used to get walked all over in friendships and relationships snd have required a lot of therapy to correct this.
Give them choices within reason. So they get to decide sometimes what they want to do and sometimes not. It teaches them to be able to get their needs and wants met without being self absorbed.
Praise them for what they have done well and especially where they have put the effort in but don’t praise them indiscriminately. Those who’ve never been given constructive criticism or had boundaries set often become the nightmare neighbours or the selfish oafs who annoy everyone.
As for you, have you ever done any volunteering or mentoring? Sometimes having purpose and meaning can help to address that sense of mild dissatisfaction.