Stop-loss orders sound simple in theory, set a level, walk away, let it protect you. In practice though, plenty of people either set them too tight and get stopped out on normal volatility, or skip them entirely and regret it later.

How do you actually decide where to place a stop-loss. Fixed percentage below entry, based on a recent support level, something else entirely. And has your approach changed after a trade that did not go the way you expected.