Dirty ceiling fans are really gross. I hate how they collect dust and then just whirl it all around the air in my house. They make products designed to help you clean ceiling fans. Most of them are long poles with some sort of attachment. I recently got a nifty Swifer type thing that helps me get the job done and I love it.
If you don’t have one of these fancy gadgets it’s still possible to clean your ceiling fans. I’ve found that a chair and some damp paper towels work wonders for the lower ceiling fans. But for the higher up fans you will need something to help you reach the distance. I’ve used a broom in the past to help me knock off the dust. It gets messy and dust goes everywhere.
I’ve also tried taking an old paper towel roll and slipping it on the end of the broom and bending it so that it has a right angle. Then I cover it in damp power towels and use that to wipe off the fans. It’s not fancy but it definitely gets the job done.