You might get a difference of opinions on this but I usually start with 120 grit and work my way to 320. On my final sandings with 320 I take a warm, damp cloth and wipe the piece down. What this will do is slightly raise the grain of the wood and allow an even sanding. I do this at least 2X. A big key is keeping the work piece clean even as you sand. Periodically blow the piece off. You don't want to keep grinding in your shavings from sanding.
On a side note on your PM, I've checked a couple (3) places and none have the 3/4" tank jets. Not sure really why you want to run 3/4"???? I honestly would use 1", but that's my opinion though!!!