I been ave down for years be it scalping to very long term stocks/commodities. Most talk about winning percentages but I don't, I concentrate on keeping low losing percentages. Matter of fact I design models to be able to get out of all entries at breakeven plus one tick, so if system entered at minus 4 ticks and out at plus one tick on original entry, made 5 ticks.
I took a gentleman, Jim, last January who been losing for years, people's lives fascinate me sometimes especially if they willing to overcome personal challenges outside of trading, so he be spending next 2 years to change his previous misconceptions of what price action means before to how I view it. So after 5 months, his losses are 0 to 2 per day trading stocks on dozen to two dozen signals and even that is too high. It is not how to manage a trade first that matters, it is taking a trade where price is screaming to not to be taken at all.
Jim is last guy I mentor. Very time consuming and I am at a stage of life of having built resources so I can travel and do activites only dreamt when learning about price action.
Managing of a trade is based on constant risk as I view it, time management, strength of trend, S/R all are studied till becomes like breathing. Memorizing is constant before the market, during and after.
And yeah, my hugest scalping losses been cause I ave down, nothing like tossing 7 figures, but eventually new equity highs after months. I don't recommend most to ave down, but I love being able to overcome my challenges.
Longer term I hedge, so if systems can't find enough hedge ideas, trade don't get done, I seek to buy very low and sell very high, but you better be able to keep overall losses very low percentages.