Your next step in the process will be to fill any holes and dings you may have from the body of the guitar. I used some Bondo (the stuff used on cars) to fill any existing screw holes or dents in the guitar. Once I filled the holes and let the Bondo harden, I took some light sandpaper (maybe 400 grit or higher) and sanded the body to a smooth finish all the way around. Again, as this being the prep work, the better of a job and more time you take doing these first steps the better your finish will be in the end. TRUST ME! Take your time and do it correctly! Anyway, you want the smoothest, nicest finish you can get in this step. Sand all the dings out. Any scrapes. Any bumps. And look everywhere! Look in the cavities, on the back, on the sides, in the horn pockets.
The trick on this step is to apply the Bondo to the point where it is a little bit higher than the surface of the rest of the guitar. That way when the Bondo dries, you can sand down the high points to make the surface flat. If you apply the Bondo at surface level, you may see some low spots when the Bondo dries and will be forced to apply a second layer of Bondo, which means you will have to... do I dare say it???.. WAIT! AHHHHH!
But get that body flat, flat, flat! Once you have your "precious" flat and smooth go on to Step 4, the primer base coat!
Step Links:
-Overview
-Step 1: Materials
-Step 2: Stripping the Paint
-Step 3: Filling Holes and Dings
-Step 4: Primer Base Coat
-Step 5: Applying First Color Coat