I'm a short term trader or scalper, it is my instinct to have a 20 pips imaginary SL, imaginary because I don't set the 20 pips SL on the trading platform if I'm monitoring the trade, if my trade is already at -15 pips then I immediately review my indicators and if the trade is against me and it's already in my imaginary SL I stop it manually. If my trade also is more than an hour to four hour and still at negative level (-15 to -19 pips) I stop my trade manually. If ever my trade is already on positive level and I have to leave my trade open while I'm away, then I'm going to set a positive SL. so basically I still use an SL.