I'm afraid you won't find me any better at it. My honest feeling is that trying to sell at the high or buy at the low is extremely dangerous. If I manage to sell within 85 or even 80% of the high and buy in at about the same I'm happy.
Fortunately I came close when selling some Noront on it's initial run but bought back in much higher than should have on the pull back. Buying seems easier but might be even harder to judge the right entry points.