In thinking through your estate planning, a document you should consider is a Durable Power of Attorney (POA). This is a document that gives someone else the power to legally sign documents and make decisions on your behalf. Without adequate safeguards, this can be a dangerous document because that person could possibly use it against your better interest.
The primary purpose of a Durable Power of Attorney in estate planning is to name someone else (usually your spouse or family member you trust) as your power of attorney, to become effective if and only if you ever become incompetent in the future. If you never become incompetent, this document could never be used. If you do become incompetent, your power of attorney could take care of your personal and financial affairs without the necessity of petitioning the Court to set up a guardianship. You can have a POA for financial matters and separate POA for health care decisions, or you can simply combine them into one POA document.
Another consideration is to have a Power of Attorney for an adult child (over age 18) who is not married. If they do not have a Power of Attorney, and become incompetent (as a result of an illness or injury), then it may be necessary to go thought the expense of a guardianship to legally care for them. They are no longer minors that you have the legal authority over. This becomes relevant as they graduate from high school or enter life on their own.