An editor’s page can look like a flurry of red hacks and slashes, the margins stacked with firm suggestions and agressive questions. Or, it can look like a gentle number of subtle suggestions, egging the writer in the right direction. The ideal mark-up probably looks like something in between.
The power a red pen can have when pointed at something sacred, something which a writer has poured their sweat and blood into, is immense.
It must be weilded with kindness and a firm respect for everything the work could possibly become.