It depends on money management and technical analysis strategy. I only allow to lose 2% of my capital in single trade. That's why I take lot size after finding the number of pips up to stop loss point. Mostly I take stop loss at 20 pips and take profit at 40 pips. I daily take about 8 trades with this strategy. You should define your own strategy to get better results. I think it is not good to follow other strategies.