I periodically clean my glass carriers with isopropyl alcohol - once or twice a year they get a bit hazy.

Other than that I use compressed air to blow out dust. I try to avoid removing the carriers from the enlarger to minimize further dust entry.

The most important dust control factor in my darkroom is a large, freestanding HEPA filter. It's designed for a room three times the size of my darkroom, which doubles as a spare bathroom/laundry room (so you can imagine the dust on laundry days).

Last winter I had horrible dust problems. It got so bad I gave up on trying to print for two or three months. The HEPA filter cleared up the problem.

I also wear a bandana on my noggin while in the darkroom. I have long hair which tends to shed a bit due to a bad thyroid condition. I also have a beard and probably should wear a face mask but so far I haven't seen any need to go to such extremes.

As Ann suggested, dust off the paper before making the exposure. I keep an Asian hake brush in the darkroom for that purpose, tho' sometimes I'll just use the edge of my palm or a squirt of compressed air.

To minimize problems on my negatives I use filtered or even distilled water whenever feasible. Our water comes from a rural well tapped into a limestone basin - I'd get actual chunks of lime scale if I didn't filter the water. There's also a brine type water softener in the well house.