Do I rough up a glass call just like a slate or is there a different method to employ here. I just picked one up, and it sounds good without any roughing, but should I scratch it up?

It will need to be roughed up, you'll find out when. I've been using the stone of a Primos Slick Stick on my glass and crystal calls. A course sand paper works too. Run the stone or paper in one direction, not circular. Use your striker by playing across the direction you sanded.

Thanks RI! That's what I needed to know.