RE: slate call conditioning
Emery Cloth...I go in Circles, back in forth.
If you are worried that these scracthes are going to make a Different sound, what about the pressure on the Stick? What about the Tilt? the Possition you hold it? What about the pressure you have on the stricker. How about the Tip of the Stricker AFTER the first call will get a slick spot.
My point is you are worring about to many things. Just try to relax and have fun!
TF