I have tried sanding without sanding disks using regular sand paper.
I have never been able to get a good finish with that technique. I
have been turning bowls for about 2 and a half years and am having to
do less sanding now than when I first started. But I still need to
sand. Some people need to sand more than others. Some bowls need to
be sanded more than others. Some woods need to be sanded more than
others. Richard Raffin (I've seen him on video start with 60 grit and
do a lot of sanding on the lathe) does more sanding than David
Ellsworth (I took his class and he says he usually starts with 220
grit off the lathe). All I know is I need to sand while the lathe is
turning and the grit I start with directly depends on many other
factors.

I use an electric drill with the lathe off on some of the end grain
problems. I also many times use the drill with courser grits while
the lathe is moving at 500 rpm or slower to get rid of tool marks. I
recently started using a passive sander (the Sorby brand) for the
finer grits. The finish is better and I don't wear out the electric
drill so fast.

I started out spending about 30 cents a piece for velcro disks at
places like Woodcraft and Packards etc. Way too much. So I found a
supplier that sold them for 20 cents a piece
(http://www.turningwood.com/sanding.htm). A bit better but still to
much for me. As of now I am punching my own using the technique at
this web site...http://www.kestrelcreek.com/Sanding_Tip.htm. Now I am
spending about 6 or 7 cents per velcro disk. I can live with that.
The only draw back is that in order to save money using this technique
you must make a larger initial investment.

Hope this helps,
Ted