The trick keeps the dust off everything below.
Slip a Pillowcase Over It Before You Dust
How to clean a ceiling fan safely, and why a pillowcase traps the dust before it falls.

A ceiling fan collects a surprising amount of dust on top of its blades, right where nobody looks, until it's bad enough to drift down onto the furniture below.
None of that calls for a messy cleanup after. One trick keeps almost all of it contained from the start.
Turn the fan off and let the blades stop completely

Turn off the fan and wait until the blades come to a complete stop before you climb up to clean it.
Why? A moving blade can hit a hand or a duster hard enough to cause a real injury, and it also flings loose dust everywhere instead of trapping it.
Protect what's below before you start

Spread a drop cloth or old sheet over any furniture directly under the fan.
Why? Even with a careful method, some dust falls, and this keeps it off furniture instead of needing a second cleanup.
Slip a pillowcase over each blade

Slide an old pillowcase over one blade at a time, then pull it back toward the tip to trap the dust inside as you go.
Why? The pillowcase catches dust as it comes off the blade instead of letting it drop, which is what actually keeps the room clean.
Wipe stubborn spots with a barely damp cloth

For dust that doesn't come off in the pillowcase, wipe the blade with a cloth barely dampened with an all-purpose cleaner.
Why? Too much liquid or pressure can bend a lightweight fan blade, and a heavily wet blade attracts more dust once it dries.
Let the blades dry fully before turning the fan back on
Let every blade dry completely before switching the fan back on.
Why? A damp blade spinning at speed can fling moisture, and it collects new dust faster than a dry one while it's still wet.
If today's a low-energy day
Just wipe the light fixture globe today, from a stable step stool. That's enough for now.
The larger lesson
A ceiling fan rewards a little planning more than a lot of scrubbing: contain the dust before it falls, and the room below stays clean without a second pass.

The pillowcase does more work than the cloth ever will.
