[gregjor]

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.