I think being aligned with money is very possible with separate bank accounts. Ultimately, it comes down to what works best for you and your family.
Bottom line, do what works best for your family. If there are trust issues, or if one partner is a big spender and needs some accountability, then by all means go for combined accounts.
1) We are not allowed to take on significant credit card debt. In addition to our own bank account, we also have our own credit cards.
2) Even though we have our own accounts, we still discuss major purchases. We do not have an exact threshold, but it usually ends up being anything about $200 or $300.
3) We let each other know when money is tight. At least once a month one of us is asking the other how we’re doing with our money. We’ve grown to just kind of know when one is in better shape than the other.