Succesful institutional traders often talk of quitting and going to trade for themselves. Only a handful of them manage to make the transition. Most traders who leave institutions get caught up in the emotions of fear, greed, elation, and panic when they start risking their own money.
It pays to write down your plan. You need to know exactly under what conditions you will enter and exit a trade. Do not make decisions on the spur of the moment, when you are vulnerable to being sucked into the crowd. Plans are created by reasoning individuals. Impulsive trades are made by sweaty group members.