Nothing gives one person such an advantage over another as to remain always cool and unruffled under all circumstances.
Thomas Jefferson
He who knows when he can fight and when he cannot will be victorious. In planning, never a useless move; in strategy, no step taken in vain.
Sun Tzu, The Art of War
Let all your things have their places. Let each part of your business have its time. Resolve to perform what you ought. Perform without fail what you resolve. Make no expense but to do good to others or yourself: i.e., waste nothing.
Ben Franklin on Order, Resolution, and Frugality