Based off of Lord of the Flies, to live well means to minimize human suffering.
Golding's motivation in writing Lord of the Flies was "an attempt to trace the defects of society back to the defects of human nature." In seeking to go back to the source, it is clear that he acknowledges that to live well means to create enough avenues for people to be left alone. The terror that falls upon the boys is the result of not having enough structures that enable people to be free from others.
The boys suffer because there are no limiting structures on the island. This "tyranny of the majority" causes pain and suffering. Piggy suffers because the group targets him. Simon is killed because the frenzy of the group knows no boundaries. Roger ends up relishing his sadistic role because of a lack of limits. In each of these cases, a world without limits makes life unbearable. A world without limits causes suffering.
At the end of the novel, this is Ralph's realization. When Ralph weeps, he does so because of the amount of suffering caused: "Ralph wept for the end of innocence, the darkness of man's heart, and the fall through the air of the true, wise friend called Piggy.” Ralph recognizes that he wanted to do so much more. He wanted to create so many positive structures. However, in the end, the best thing he could have done was to simply establish that everyone should be left alone. He failed to establish limits on human suffering caused. The ability to be left alone is the recipe for a happy life. The limitation on human suffering is a recipe for a happy life. Ralph weeps because he wanted to do so much. Yet, the most basic thing in terms of enabling his friends to be free of pain was something he failed to do.
The best thing we can do is to minimize the pain caused to others. To live well means to live a life where happiness might not be the most important element. Rather, it is to simply do as little harm as possible. When the "ethical nature of the individual" is geared towards minimizing suffering, happiness can be found. If this becomes our goal in life, we can live well.