Advice for creating a joint bank account with a spouse?

You go to the bank and tell them you want to open a joint account. Simple process. The main advantage is not having to constantly transfer from one account to another.

If you meant to ask how a couple should manage joint finances, that's a larger question with no single answer. Disagreements or differences of opinion about how to handle finances cause a lot of conflict in marriages. A joint bank account is merely a convenience, not a solution if the couple doesn't agree on how to handle money. What works depends on the individuals, so probably best to discuss the expectations and how to handle finances and money together.

If you meant to ask how to keep your assets separate, with some joint assets, that depends on state law. If you have that concern you should consult an attorney.

What works for us is to have a joint account as well as each of us having our own individual accounts. We both set aside a portion of our income as a kind of "allowance" that goes into our individual accounts, and the rest into the joint account. All household expenses gets paid from the joint account. How we spend the money in our individual accounts is entirely up to us, but any optional expenses (hobby, vacations, date nights, etc.) come out of our individual accounts, not the joint one.

We found this to be excellent for us. It eliminated a lot of confusion and dispute (because you don't have to explain, justify, or get permission to spend money from your own account), and the surprise bonus was around gifts and date nights -- if you're paying for those things out of "shared money", that's fine, but if you're paying for those things out of your own, private money, that makes it more of a gift.

There isn’t much to it. Credit unions often have the best rates. You’ll also want a safety deposit box for things like birth and wedding certificates, car titles, etc

You are already on the hook. Keeping separate accounts will not insulate you. (If that is what you are getting at).

Also, for joint investment accounts, look into a JTROS account (Joint Tenancy with Right of Survivorship)