When entering into the stock market you need to have a plan for your trade. Fail to plan means you are planning to fail. After you have a plan you must be disciplined with your plan.
Think about all the conditions that could happen in the future. But don't focus on the condition. Instead think what you should do when it happens.
For example, if you buy a stock at $5, you must set at which level you want to cut loss and take profit. If the stocks went down, would you add position or not. Will I close my position if the stock didn't reach any level that you want.
Planning a trade is similar to planning for a travel. You must plan for every events, especially the unpredictable. What will you do when the market crash or the company announces earning surprice. You must plan for the unseen.
Once you have a plan, you have to stick with your plan. Ignore any one that says something about the stock. Just follow your plan no matter what. That's why you need a solid plan. You must ignore if some guru saying to sell your stock that you have enter.
To be a succesful investor, you must never trade with emotion. The only way to eliminate emotion is to have iron disipline on your plan.