About the only tweaking I have done is with colorants. But I also do change up firing schedules/cooling times/holds/ temps and that sort of thing. I would like to take a serious glaze workshop. Or a workshop to teach me how to use the software..... I recently have been using a different clay. SB red by Laguna. I really like it. But I noticed that some of my glazes had some small pinholes. I decided to try bisquing to a lower temp. That seemed to help. Now I am going to increase the hold on the glaze fire and see what happens. That is the sort of tweaking I do.