Well, this is just my experience. There might be a better way, but what I've discovered seems to work very well. See the photo - that's a Chinon 5.25" floppy disk drive. It's really good, and I'd recommend one. The can beyond it is a compressed air canister. The floppy disk about to be inserted in to the FDD is made by Leica.

I bought a sealed "NOS" box of them, and initially I thought they were poor quality. Every one of them produced write errors, when I was using the excellent VGACopy DOS disk copy program. I then used the "Dust off" can, and blasted air from a distance of about 1-2 feet, towards all 4 sides of each Leica floppy disk. I then retried each disk, and all of them now writes and subsequently reads 100% error free.