An initial sand with 80 grit, second sand with 150, and a final sanding with 220 grit sandpaper. Sanding really is self-explanatory and is truly difficult to entirely messup, except for one important step that must be done before any decorating and varnishing is done...wetting the grain.
After going through the 3 rounds of sanding, I use a dampened sponge to wet the wood if I'm in the city. The pic on the right is a laminated walnut maple paddle being wetted on the condo balcony "workshop". If I'm up at the cottage, I take the paddle for a dip in the lake and give it a brief test-drive. Either way, the resulting hydration causes the wood to raise and eventually dries forming tiny sharpened ridges following the grain pattern. This needs to be resanded with 220 grit to remove and results in a permanent smoothness to the wood. I'll confess that after handsanding a dozen or so paddles, I cracked and purchased a Random Orbital Sander to do most of the gruntwork. It's loud and dusty but saves the hassle and time to devote my energy to more creative things like the decorating.
At this stage, I hang the paddle in my locker room using some dollar store utility hooks suspended on the mesh wiring of the locker cage and reflect on some decorating inspiration. Hanging the paddle (rather than leaning against walls) ensures that the shaft doesn't warp and is the best way to preserve the paddle's integrity after doing all this carving work. Next up...paddle artwork.