Having the strings low in the nut and pinched on the sides often produces a more subdued, mellow tone. With the wound strings about half in/half out at the nut and moving freely, but not loosely, you’ll get more sustain and “oomph”. We’ve reduced the surrounding nut height numerous times to very pleased customers. No need to get the unwound strings half in/half out, but they should be moving freely.
Another factor to consider is the player’s style. With the wound strings half in/half out, this allows for the player to be aggressive without the strings edges of the nut breaking off as the strings are strained. Please see Dan Erlewine’s Guitar Player Repair Guide.
-Step One – Remove strings and tape off all sides of the nut.
-Step Two – Draw a line for the area to be removed.
-Step Three – Use a sanding block with 100 grit sandpaper to lower and reshape the nut’s top.
-Step Four – Use a progression of 220, 320, 400 grit sandpaper to smooth the nut. For a polished look, progress to 600, 800, 1000, etc grit sandpaper.