From David Nassar's book:
Live within your means. Many people will live far beyond their means in the belief that things have always worked out and will continue to. This is unfair pressure to put on yourself if you are to be of healthy mind while trading. Financial pressure is precisely a reason that you should not trade. The emotions associated with such pressure when living beyond your means jades objectivity and, in the end cheats you. When you money motivation is the only reason to trade, danger is not usually far behind. This rule can apply to, other professions, or life as well.
Trade without desiring results. Therefore, no matter what is happening in the market, up or down, no matter what is happening with my PNL, positive or negative, no matter what is happening in my life, my best response will always be the same: Calm, Cool, and Absolute Discipline to my Trading Plan.