I've recently had the chance to spend time a >1000 year old family. I was deeply impressed by the cultural health, vitality, and reflection present in this family to this day. If my family were to do half as well after two gens, I'd be blessed. Here's what I learned from them:

1) Trust is everything. Trust funds destroy Trust. If your kids don't inherit your wealth unrestricted, they'll never take full responsibility. You can't raise someone to be a leader if they know they'll never be in charge. If they can't destroy it, they have never owned it.

2) Branding is everything. If your family doesn't have a brand and rituals, and being a part of the family means something, then it won't stick. You need a name, traditions, rituals, ... At least have an annual family dinner at a special location every year.

3) Someone needs to be in charge. Aristocracy handles this often with the first-born son inheriting most of the family business. You don't need to do that. You can even elect someone (for life). But you need to figure out how to figure out who is in charge.

Regarding 3): My own thinking is that it might be better to not split business and property into shares too much. Give children whole things to be steward of, don't give them some abstract non-voting stake in the family business.

Also don't give them a trust fund. Give them something they can own, grow, and lose. Then they have to take responsibility.

4) Choice matters. Even the person who is destined to inherit the family business needs a choice to walk away. Nothing that isn't chosen has any value. If you try to force your kids to be responsible, you'll destroy everything overnight.