I do but not always.

A lot of time actually. It is hard to predict what could happen with bitcoin and a lot more with altcoins. Many have tried to predict but most of the time they fail. I remember one in facebook which is paying if you guess the right price. Out of the many comments it is like 5% are right but it is just a guess without facts provided.
yes i also have the same situation, for some time i do trad on right time and it really give me good profit but some other time it is not so much profitable and it cast a big lost.
Its impossible to match the perfect timing every time as we don't know what will happen next in bitcoins and majority of times we may buy or sell bitcoins at the wrong time.
That's right. There is no such thing as perfect timing here. In 90% of cases, my timing was far from perfect, what's important if it all works in the long run.