I agree with Richard G. Scott when he said:
Righteous character is more valuable than any material object you own, any knowledge you have gained through study, or any goals you have attained no matter how well lauded by mankind.
That idea sounds a lot like how Clayton Christensen suggests measuring one's life. (From Inspirations)
Elder Scott ties several other traits to character:
Another trait I believe that is tied to character is courage. It takes courage to do the right thing and stand for true principles, especially when it is hard. But like Elder Scott said:
character is not developed in moments of great challenge or temptation. That is when it is intended to be used.
I think a measuring stick to judge my character is what President Thomas S. Monson once cited from Christan writer Charles Swindoll:
The real tests of courage are much quieter. They are inner tests, like remaining faithful when no one’s looking
By simply being the same person when no one's looking as I am when I'm around others (every day), I believe I'll be developing my character. It takes faith, consistency, integrity, and courage, but I believe the reward is worth it.