The easy point is looking at charts from different timescales. Is this the lowest point this week? This month? How is it doing this day? Buy in red candles. The hard part is deciding if this is the lowest point. In fact it says close to nothing if a coin reached it's lowest point in a month. In the current bear market it can easily plummit further. To ease this hard part you can look at FA points like upcoming milestones or at TA indicators, but this doesn't guarantee you anything, it just reduces risk.