Pin bars are formed before the change of the trend. You can entry in a pin bar if and only the next candle breaks and closes above the high/low of the pin bar candle. The timeframe I usually use is 1,3 or 5 mins, for intraday trading (depending on the market).
We get to see that the market reverses very aggressively after a pin bar is formed. Initially your risk-reward ratio should be at least 1:2. Aggressive traders move there stop loss to break-even, when the price reaches 1:1 (RR Ratio) to make sure that they are not missing the new trend.