I've had pretty good reliability with 3 1/2" disks, if
you keep the drive clean, and make sure that the disks
aren't dirty or have that "gritty" sound to them, they
typically work OK.
I typically use the fdformat (or superformat) under
Linux - you can have it format the whole disk before
going back and verifying, sometimes it might take a
pass or two before the disk verifies OK. Degaussing
the disks with a bulk eraser would be a good idea too.
But be sure that your drive is good and clean. I've
also had better luck with older floppy drives -
Mitsumi, Chinon and Teac drives seem to be very
reliable. Blow the fuzzies out before use.
Also, be sure your BIOS is set right - I had a hell of
a time a couple weeks ago trying to write a disk on a
PC here, it was just a simple boot disk, but I tried
four floppies, checking the image, reformatting, etc -
then I remembered that last time I used the PC, I had
a 1.2mb 5 1/4" drive as drive 0. Bios was set wrong,
and the whole time I was trying to write data to the
disk at the wrong data rate. Doh!
-Ian