There are many trading styles. I just have found that throughout my trading career that the safest trades are when stock remains above the 10 day moving average if you are a swingtrader or stays within an upward channel if you are longer term holder "INVESTOR".
First I agree that double bottoms are one indicator that may show a reversal in a stock, however there needs to be other supporting evidence to make the entry.
Improving MACD, OBV, STOCHS, RSI, to name a few... In addition, resistance, pivot, backtesting, Moving Averages, Trendlines, and support levels need to be evaluated.
On many double bottom "boxes" that occur below the 10 day moving average your will find the 10 day moving average then becomes a resistance level.