OVER TRADING
This particular one is really an important problem with many traders and I personally made that mistake so many times the I lost count, I deeply believe everyday you should have a specific target for the amount of profit that you want to have and after that you get to that point you should be able to quit doing any more trade, and sit back and relax for the rest of the day.
When you're just getting into more trades over and over you're increasing the chance of you losing money eventually, and it's not only when you got some profit either, you should also have a limit on how much loss you're willing to take on your trades, for example you should set a rule for yourself that if you got into 3% loss in a day you should stop trading and if you don't do that then that will lead to to get in more trades in the hope of profit and that would be called revenge trading which usually doesn't have good results.