i had issues with humidity and the sound hole sinking into the body.
all rules mentioned above are great but check the bow of the belly with the straightedge.
maybe its convex......thus increasing the action. not sure how much humidity you have..
if all is good, then get the sandpaper out. Just make sure you keep it even so the saddle nut fits
flush to the saddle slot.
here is a good reference..
http://www.larrivee.com/features/humidity.phphere are some measurements from my acoustic so you can see if the top of the sound hole is sinking in....which is a
common low humidity issue..
top of 12th fret to low E string is 5/64
top of 15th fret to low E string while holding 1st fret is 5/64
top of last fret to low E string while holding 5th fret is 5/64
if your measurements increase when going up the neck, then the sound hole is sinking in.
you can try throwing some damp sponges in Ziploc bags with holes to try and get it back...kinda like over humidifying it..
usually i just shave the saddle nut if the guitar has not been properly humidified and the wood has basically settled to a constant state.....this gives me better action and no stress worrying about humidity as the guitar is shot but still playable..