Diy...
few things you need.
1) sand paper ( 180, 400, 600grit )
- sand from roughest to finest for that baby bottom smooth satin feel.
- Sand in ONE DIRECTION , tape up parts of the neck you dont wanna sand as a precaution.
2) Lemon oil. the nourish and revitalise the neck surface.
3) Patience - do it slowly and steadily.
** try not to sand through the paint. its hideous. Sand abit off the poly finish then fine sand for the smoothness.. this way the poly still protects the neck surface from dirt and etc... **