There is no doubt that most traders if not all would have made or are still making the same mistakes.
   Making trading mistakes is part of every traders journey, whether completely new to trading or has been trading the markets for decades but still make some common trading mistakes.some of these mistakes are deadlier than others. The fact is there are some mistakes that are hard to accept for some traders. Ignoring a mistake and repeating it over and over again can spell the difference between becoming a successful trader or loosing one.

Letting profitable trades turn into loses is one of those.
  If you are making this mistake you are not alone.even some guru traders are guilty of this common mistake.
How many times have you perfectly timed your entry seen nice running profits only to see it melt down by a sharp reversal? (Though manipulations do occur at some point) I'll bet more than once.
Letting a profiting trade go bad is very annoying mistake but there's light at the top of the tunnel.
    The best way to correct this is by planning. Know your exit before entering a trade and develop your own trading exit strategies.  You could use wild trailing stop for trending markets which are the best trading markets I'll recommend.
   You could also take a bit of your position off when the market makes some profits available.take a bit more as the move progresses and leave some on for the big wins. This process will help you take some profits and avoid sharp reversals.

Please do well to add your own strategy maybe it could help someone.

Most novice traders hold on to loses and let go of wins. Sounds ridiculous when you loud it yet several studies have shown that it's the most common mistake made by traders. It is simply our humanity and the completely irrational but understandable fear of loss.

The principle is simple.

When we start winning we get anxious about loosing our gains .we close trades prematurely to capture the profits before the price starts to drop again.wereas we should be holding on to it and closing appropriately to maximize the profit.
     Conversely,when we start loosing we hold on to the losing position longer in the hope it will turn upward at some point.we have the irrational beleif that we will reduce or wipe out the lose without proper re-analysis.

This is thesame principle that casinos exploit to keep unwitting patrons pulling at the one-arm bandits until their bank accounts are emptied.
  So even if we have more winning trades than losing ones, the average size of the wins versus the loses finds us in a net lose trading position over time.
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It is the most basic and destructive mistake a trader can make and if left unchecked could become habits that would be difficult to break.

Please do well to add your opinions on this as this post is pron to corrections and contributions. Thank you.