This website (http://obituaryguide.com/writeyourown.php) says,
Why not get started on writing your own obituary? This is your chance to say what you want others to know about you. Do it for yourself: for peace of mind knowing that you have had your say. And do it for your family and friends: that you have helped them cope with a difficult time.
Your best chance of having your wishes honored is to write them down. Writing your own obituary can be part of your life and end-of-life planning. The way you would like to be remembered is part of a careful arranging for yourself should you not be in the best of health or life.