Hey man, just one thing to be aware of when wet sanding, especially on the headstock's is to be very careful about water dripping down into the tuner holes. It doesn't take much for water to get into the unsealed grain and start expanding things. I've had it happen and it sucks.
A great little tip from Jarrod was to get some clear coat, (or even the paint you're using) and, with a cotton bud, go round dabbing the insides of the holes to seal them. Just squirt some out of your rattle can into a jar lid or something similar.
This way you can wet sand to your hearts content without fear of ruining your headstock, especially when all the clear coats are down and you're doing the finishing wet sand.