Day Trading is an art and you should be a highly skilled artist to win the trades. When I said it is an art do not think that there should not be a scientific approach towards it. One should be very much skilled in mastering at least three to 4 technical tools to make a successful system for day trading. And it make sense if you use a system created by you, because finally you are the one who psychologically approach each and every trade done by the system. I personally believe that the win and lose of every trade is effected more than 50% by the traders mental attitude.
A day trader typically trades several times in a day with a gain of few points per trade and close out all his positions by the end of the day. Unlike investors a day trader will hold the position for some seconds may be for some minutes. Yes it is always wise to have a trailing stop lose if your trade is moving your way. It is a very dangerous way of trading if one is not doing it with sufficient stop lose. See the performance of our day trading tips here.