There is a saying: "cut your losses and let your winners run." I know that is not what some people teach, they say when you get some profit you should bank some of the profit and move your stop loss to a break even. That way you will not take a loss on the trade. They are saying that when the market is moving in your direction, to get out before you lose-just take a little bit of the profit on the trade. I have often wondered what their exit signals are if they are willing to close part of a trade and see what the rest is going to do. That seems like gambling to me. (Lets see what happens.) This tells me that they do not have a good exit strategy.
I think you should start out small like trading only one lot to start with. When you see add on signals you should add on 2, 3, 4 or more lots once the trend is truly telling you which way the market is going. If they have a good exit strategy why are they only closing a portion of the position? I say why not close the whole trade if the market looks like it is going to turn on you. If the market retraces a little, and takes off again, you can get back into the trend.