if the stock price is on the slide and the RSI is hitting say 20-30 its usually a good place to start cautiously start looking for a long position - BUT a signal that is really bullish is when you get the price continuing to fall without the RSI making a lower low. That is on the first dip, the RSI hits 20, then the price falls lower again but the RSI rises to 30 or does not make a lower low.
This is knows and "bullish divergence" and is a very strong indicator that price wants to go higher and usually signals that a reversal could be close.
