Well, there're these things you do when you're older (cough cough). "Older" is different for different people, with the factors of family, children, parents, income, inheritance, assets, and location being first order parameters in the equation.
Of the things every household to be adulting well, even those households of one, the top three are:
1. A will
The legal document listing what you have, where the big things are, who gets what, and how you want the legal ending of your life to be handled.
2. A medical directive
What happens if you are disabled or unable to decide for yourself? Who decides to pull the plug, and do you want them to pull the plug? These directives vary by state.
3. A spreadsheet or other document listing all bills, the bills account numbers, how they come in (paper, electronic, push or pull / sent or received), and how they are paid.
For single person households, this helps the person who has to close your accounts be able to process the accounts as needed.
For multi-person households, this helps the person who doesn't pay a particular bill, or all the bills, know what bills are legitimate, when to expect them, when they are due, how they are paid, and where the funds are.
Now, also recommended is term life insurance. This is a short-term policy with which you are betting you will die before the policy ends, thereby forcing the insurance company to pay your death benefit which is the amount you selected at the beginning of the term; versus the insurance company which is betting you will stay alive for longer than the policy, at which end they will pay the entire amount you paid back to you at the end of the term, minus inflation and the interest they made on the money you paid them in your bet. That's the cynical view. The non-cynical view is life happens, hope for the best, plan for the worst, and do what you can to minimize black swans.
Along with all of this, having a lawyer who can help you through this process is strongly recommended. Said lawyer can also help your family or those dealing with cleaning up your life after you go, with navigating the ins-and-outs of the process.
Those are the big ones. For a household with more than around $200,000 in worth, a trust is recommended. That sorta assumes you have a family that can trust with you.
And the last of the adulting commentary of the day, review all of the above things periodically. In particular, review your documents every 2-3 years (set an alarm in your phone calendar app for next June, put it on a yearly repeat), and after every major life event, including but not limited to changes in marital status, purchasing or selling a property, large changes in estate value (economic windfall, catastrophic loss), and major health diagnoses.