If you are serious about making and keeping money by trading stocks, then there are three things you need to do, and do well.

Money management

Money management comes first. Without a rock-solid method of managing your trading funds, you trading results will be only be fair at best. Money management is more than just knowing how much money you have tied up in a trade. It's a method of using the right portion of your trading account on any one trade relative to the perceived risk and reward.