Investing is a long-term strategy that requires discipline and a clear head. It's important to never trade based on emotions, as decisions made in the heat of the moment can often lead to costly mistakes. 

One key principle to remember is to avoid greed. It can be tempting to hold out for bigger gains, but it's crucial to take profits when the opportunity presents itself. As the saying goes, "No one ever went broke by taking profits."

By staying disciplined, avoiding emotional trading, and taking profits when appropriate, investors can set themselves up for success in the long run. Stick to your investment plan, remain patient, and focus on making informed decisions rather than reacting impulsively.