As for parameters, the hard stop which is always in place with the entry order is 6 pips. Never lose more than that is my top rule. As soon as it goes my favour I make it even less, like 3-4 pips or whatever price action suggests. The rest is up to market conditions. Occasional lucky run I can hold for 20, 50 or any other amount of pips as long as it really is travelling that way, but as such one way moves are relatively rare, most "scalps" end up as 9-15 pips in the pocket (in the case of a winner of course).