Things You'll Need
Instructions
Talk to your dungeon master. Every DM will have a slightly different take on the concept of chaotic good. Some will emphasize the chaotic, and some will emphasize the good. In most cases, a chaotic good character assumes that the a good outcome is more important than acting within the law or with "good behavior" all the time. The character will not take an overtly evil action but isn't above bending the rules.
Evaluate your actions based on both your whim and the ultimate outcome. Lying, a minorly "evil" act, might be justified if the character is lying to get information or if it results in saving innocents. Killing evil creatures might be appropriate, or your character might sometimes have a good heart and expect evil to reform. Either are acceptable, depending on the chaotic nature of your character.
Choose your actions based on your mood. When two equally "good" options present themselves, flip a coin or role a die to determine how you choose to respond.
Question the law. A chaotic good character bases her moral judgment on her definitions of good, not on the law. So, for example, in a land where slavery is legal, a chaotic good character might free the slaves just because she finds slavery morally objectionable.
Remain motivated by your god's definition of good, not by loyalty or other party members' opinions regarding the choice. A chaotic good character may decide that the King giving him an order is unjust and therefore refuse to obey. Civil disobedience is the rallying cry of the chaotic good character.