Talk about it. The most important thing you can do to prepare for the inevitable end of life is to discuss it with your family and the people close to you. Tell them what you would like. Ask them what they would like.
Get input. It is also important to consider what your family can manage, financially, logistically and emotionally.
Gather information. There is a great deal of information that your survivors will need in order to handle your affairs after you die. You can help by gathering this information together and making your family aware of its location. There are helpful checklists, for example, this printable pdf "Information to be assembled before death" (thanks to an FCA affiliate in CA).
The FCA planning kit "Before I Go, You Should Know" (provided to our members) is a handy fill-in-the-blank booklet that prompts you to record your decisions and the locations of your important documents. (You may also purchase copies via the national FCA bookstore.)
Why plan ahead? When death occurs in a family that has done no advance planning, the survivors may accept conventional and costly funeral arrangements because of social pressure, emotional stress, or lack of time.
Planning ahead is the most loving gift you can give to your family and friends.
By making plans now, you can make your last wishes known and ease the burden on your survivors. They can then focus on grieving their loss and celebrating your life, instead of having to figure out what you might have wanted.
Pre-pay? Setting aside funds (e.g., in a Totten Trust, a Payable-On-Death account at a bank) to pay for your future funeral may give you and your family peace of mind. However, beware of prepayment ("preneed") contracts with funeral homes or insurance companies. Consider the risks involved. Read FCA's pamphlet, Prepaying Your Funeral: Benefits and Dangers (pdf) or this ElderLawAnswers page, Pre-Paid Funeral Plans: Buyer Beware.