A trailing stop aims to adapt protection as a position moves in your favor. Problems appear when it is moved too early, too far away or differently on every trade. A journal helps determine whether the management is repeatable.
Track the rule, not only the final stop
Record what activates the trail: a defined R level, a new high/low, moving average, ATR, structure, time or a discretionary condition. Also record the distance used and any later adjustment.
Compare the exit with favorable excursion
If you track maximum favorable excursion (MFE), compare how much R the trade offered with how much you actually captured. A consistently large gap may indicate that the rule gives back too much; very early exits may suggest protection is too aggressive.
Segment by strategy and volatility
The same trailing method may behave differently in trend and reversal strategies or across very different volatility regimes. Analyze groups before changing one global rule.
Compare versions without overfitting
If you test a new rule, apply it over a defined block of trades and compare metrics such as average R, expectancy, drawdown and winner size. Avoid changing parameters after every trade.