Good writing advice can be found in all sorts of places.
This page, for example, features a set of maxims for stage magicians. Some of them are fairly magic-specific (“Look after your hands and nails. Make sure they are clean or painted”); others, though, hold true for anyone working in the arts and entertainment fields (“Making things as easy as possible for your audience comes before making things as easy as possible for yourself.”)
Though I suspect it never hurt a writer to have clean nails, either.