Here is where I get rid of all those ugly squiggles and make a sleek, sexy guitar body outline. My weapon of choice, the Mighty Rigid Oscillating Spindle/Belt Sander.
I don't want to sound like Norm Abrham or your highschool shop teacher or the guy at the gun range, but after years of not protecting my hearing around strip mine equipment, firearms, and power tools, my ears hurt...So...I wear these now.
Convex corners are done with the belt sanding attachment to preven spindle indentations. Those are a $%^&* to get out after you have routed your body with an indented template.
Concave corners with the spindles
Then I hold the template up to the light to see if I have any bumbies or indentations.
Close but needs some more work.
After I get it as close as possible with the sander, I grab an old fashioned sanding block and refine all the edges.
Now inspect the egdes for uninterupted sanding marks. alternating sanding marks indicate bumps and indentations.