1) Continuously study the charts. If price action reverses look across the chart at that exact price point to understand why. Follow that price point high or low or close across the chart. What happened at that exact price point earlier on the chart? Was is support/ resistance? Breakout? Is this a rule of thumb? How often has this "rule" occurred?
2) Never keep your P/L on screen. If you are using risk management and trading your plan then seeing a loss or gain can only hurt you psychologically. Determine your risk. Determine your entry. Determine your exit. Make an OCO trade. If you are making longer intraday trades either move your stop to break even or manually trail your stop to a profit point and let the trade run.
3) Be reactive, not predictive. My biggest losses have occured when I knew the market was going to do something even though the probability was only about 50/50 or less, all because the market played me for a fool and I operated outside of my rules. It's one thing to fade a breakout with a proper stop, it's another to bet on a breakout because two amazing trend bars push right up to the prior high only for it to subtly reverse over a multitude of bars making it appear it might still break out while slowly boiling me like a frog. You made rules for a reason. Stick to them.
4) Trading based solely on patterns like Head and Shoulders, Cup and Handles, etc. is a sure way to lose money. I remember reading Technical Analysis of the Financial Markets years ago and thinking I was a TA genius now that I knew all of these great setups. Blew up my entire account in a month. There's more to trading then knowing chart patterns and setups.