Step 6: Sanding!
Remember, sanding shapes what you cannot do with filing.
Filing just gets rid of the wood you cannot with sanding (you can but it'd take forever)
Sand with sandpaper starting at a low grit, and eventually make your way up to higher grits.
I started at like 80 and wound up at 400. I would advise you to go up to maybe 800 (I just didn't have anything higher)