The root of our ethical system is personal responsibility. We have no written laws to follow, no codes, no repentance and forgiveness. The "do as you will" bit isn't enough. Everything you do or don't do has consequences that ripple through the universe, and you are responsible for them! An experienced Witch should be one of the most moral creatures on the planet.
An ethical structure is not a line with a beginning and end. Our world is about cycles, and as such, ethical structures are like spheres with all parts resting on all the other parts. The most important of these parts is HONESTY. Honesty with yourself- completely, objectively, and perfectly honest. Know the difference between being honest and being brutal, however, or you will be distracted by punishing yourself!
In order to construct your own framework you must be able to look at things honestly and fearlessly, and in order to do that you must not pre-judge them, but be objective and think clearly. And never punish yourself for your shortcomings...strive instead to correct them.
Once you learn to look honestly at cause and effect, you will be able to accurately judge the effort these changes in yourself will require, and decide if it is worth it. Once you learn to look honestly at the situation around you, it becomes malleable to your will. At the very least, you can change your attitude about it once you understand it.
Understanding comes with this kind of honesty. Understanding does not mean or imply agreement or even sympathy.
HONESTY
CLARITY OF VISION
WILLINGNESS TO FACE THE TRUTH
Willingness to act on that truth once it is faced.
The knowledge that we can never have all of the Truth.
The willingness to admit our own mistakes.
The willingness to learn from them.
The willingness to change our minds if a new fact arises.
The willingness to forgive ourselves.
The willingness to be judgemental.
to be continued...
based on Robin Wood's When, Why...If
Also, check out this great article on Pagan Ethics and Ettiquette