get sanding on the body, down to about 320 grit.
Any finer and it hinders absorption a bit. Don't sand the top cap at all or only a very small amount, because they are very thin and you don't want to go through it to the timber underneath.
Get rid of any rough spots and glue spots etc.
You could wipe over the guitar with a damp cloth prior to sanding , this will help highlight any glue issues and give you a good look at the figure in the top cap