1.  Refusing to define a loss.

2.  Not getting rid of a losing trade when it is obviously a loser.

3.  Getting locked into a bullheaded opinion about market direction.

4.  Focusing on monetary value of trade instead of market structure.

5.  Revenge trading to recoup a loss.

6.  Not reversing a position when the market is clearly changing direction.

7.  Not following the rules of your strategy.

8.  Planning for a trade and then not taking it.

9.  Not acting on your intuition.

10.  Giving back recent gains due to overtrading or inconsistency.