Scalping is really all about making 10-20 pips per trade. When you make a scalp trade always take into account the spread that you have to pay per trade. Most of the time the spreads on the liquid pairs like EURUSD and GBPUSD will be something like 1-3 pips. So when you enter into a scalp trade, you will have to make a profit of 11-13 pips in order to cover the 1-3 pip spread. Watch this video by Boris Schlossberg that explains a scalping strategy for making 10 pips per trade on the M5 timeframe.
This is a simple M5 scalping strategy that entails waiting for price action to go beyond the upper or the lower Bollinger Bands. If the price action goes above the upper Bollinger Band wait for at least 2 candles to be formed above the upper BB. If two candles formed are above the upper BB, go short and look for a TP for 10-15 pips.
In the same manner, if price action goes below the lower BB and two candles are formed below the lower BB, go long and look for a TP of 10-15 pips. You can try this scalping strategy on the demo account and see what is the win rate. A variation to this strategy would be to look for a bullish or a bearish candlestick pattern forming very close to either the upper BB or the lower BB.
For example, if a bullish Engulfing pattern forms very close to the lower BB, you can go long and look for 10-20 pip profit. In the same manner if a bearish Engulfing pattern forms close to the upper BB, you can go short and look for 10-20 pip profit. Now suppose a bullish Engulfing pattern forms close to the upper BB, in that case you will stay out and not make a trade. Price has already moved close to the BB which is 2 standard deviations from the average price and in more than 90% of the cases will make a retracement and come back within the BB pretty soon. So in this case using BBs will filter out a bad trade.
In the same manner, if the bearish Engulfing pattern is formed close to the lower BB, you should stay out and not make a trade. Similarly, if the Engulfing pattern is formed within the two BB maybe close to the signal line, you should again avoid making a trade. What we are doing is using BBs as a filter to filter out bad trades.