For me, planning for catastrophe stirs up a restless twitch in my leg that inevitably leads to procrastination. I'd call it optimism, but I think I'm too cynical for that. More likely I just hate the dread that comes with thinking about catastrophes. But, you owe it to family members. If you become incapacitated, your immediate family will either (a) be able to grieve without the stress of determining your wishes and dealing with all the red tape surrounding end-of-life decisions, or (b) be inundated with time-consuming and expensive legal action while coping with the guilt and anxiety of having to make difficult decisions for you because you didn't make your wishes known, meanwhile spending thousands of dollars a month for constant medical care. But there's more: families are often torn apart by disagreements about your wishes, whether for life-sustaining treatment, control of your finances, or who gets what from your estate. Prevent the turmoil and pick option (a).
The good news is that picking (a) is easy. Here are some of the documents you will need:
Health care directive: Washington's Department of Health provides a full explanation of what a health care directive does and a template for you to use. A directive allows people who do not want their lives prolonged artificially to make their wishes known and legally recognized.
Durable power of attorney for health care: The Department of Health also provides a full explanation and template for Durables. A durable power of attorney document appoints someone you choose to make health care decisions for you when you cannot make them yourself.
Durable power of attorney for property and finances (general durable): Similar to a heath care durable, this document appoints someone to control your finances if you are deemed unable.
I can't find a free template online, so you should consult an estate planning lawyer.
There are several other documents you should be aware of, including Do Not Resuscitate Orders and Life-Sustaining Treatment Orders. Get a good description of those here, and wills here.
Remember to get witnesses' signatures and notarize your documents so they are valid in states other than Washington (each state has different requirements).