I prefer a shear scrape, both inside and outside the bowl for my finish cuts. To shear cut near the rim, this has to be done before the rest of the bowl is hollowed out, at least on bowls over about 10 inch diameter. The walls will flex with even the very lightest tool and hand pressure. This pretty much leaves about the best surface possible prior to sanding. I almost never have to resort to 80 grit any more. In the cases where I do, like Mark said, I go from 80 to 100, to 120, to 150, to 180, and up to 400. The main reason behind this progression is that it is easier to remove the grit scratches from 2 grits back if I take this progression.
One other thing, I always use oversized discs, as in bigger than the sanding interface pad. If they are both the same size, even if the disc is perfectly centered on the pad, the edge of the pad will leave 80 grit scratches.
I have heard many say to blow out the bowl after each grit. This is supposed to remove any grit particles from the previous grit. Well, I might have tried that once or twice, but it blows dust every where, even at low air pressure. So, I took to wiping down the surfaces with my hands. I never once felt any grit remaining.
I did experiment with the Abranet type abrasives. I found that the lower grits, up to about 180 or 220, would not cut as well as the standard abrasives. Guess it is because of all the open space. Above 220, there is pretty much no difference in how they cut.
Never liked wet sanding. The sludge would fill holes that I wouldn't see till I applied finish. If there is a lot of tear out, getting the wood very lightly wet, and then taking very light passes with a freshly sharpened gouge can remove most of the heavy tear out.
robo hippy