My mum and nan always say "First you give them roots, then you give them wings" which for me sums it up. Essentially i think this means give them a happy, loving, stable, secure environment in which they feel free and confident to explore the world and gain a growing independence that will one day see them ok in life. In a practical sense, stuff like:
Let them fall over occasionally, but always be there to kiss them better and show them how to do it better next time
Let them win sometimes, but let them lose other times so they can see that they are still valued even when they don't succeed but that not everything will go their way in life
Let them cry occasionally, but always be there to help them calm down when they can't do it for themselves
Let them laugh and play a lot, but provide some boundaries when they understand more about the world around them and how their actions can affect other people
Show them respect, manners, courtesy and kindness and they will treat others that way
Let them see anger and sadness occasionally because they're real, but let them also see that people are resilient and the bad times don't last forever
I suppose finally, don't suppose that your LO is predisposed to mental ill health and there is nothing you can do about it. And this includes not getting too hung up on trying to do everything perfectly. Go with a flow but stay true to your values, whatever they are. 