It's funny that this would come up. Just a few months ago I was follwoing three Qs, and after making a good profit on each of them started to get cocky... rotating in and out of holdings, selling in anticipation of resistances and buying in anticipation of support levels. It just so happened I more than eliminated all of the previous gains by selling too early into a run and then buying when it had nearly run its course. Still to this day makes me sick to the stomach.
Still, it can probably still be done, but my position, too, would be to hold the majority and trade a few only if you have to (pay the bills for example).