When you put your affairs in order, you reduce the chances for conflict after your death. For most individuals, a Simple Will will suffice to avoid these issues. A Simple Will notifies your executor what assets you possess, and how you wish those assets to be distributed after your death.
If the worth of your estate is approaching $5 million, you should seek the services of a professional estate planner. However, for most people, a Simple Will is sufficient to put their affairs in order.