Protect your cartoonWhen grinding a lot of pieces, you can place a piece of clear float glass over top of your paper pattern, or encase it in plastic to protect it from becoming wet. Then you won't have to grind, dry, test, and repeat. You can just grind and test, quickly grinding where needed.
Placing your cartoonAlso try to have your pattern where you are test fitting right beside your grinder, to cut down on time spent moving from grinder to pattern.
Grinder resevoir maintenanceRinse out your grinder sponge often (at least daily), and replace when it becomes deformed.
Clean out the ground up glass in the bottom of your grinder regularly with a narrow putty knife. Scrape it out into a small old plastic container with a top, and then throw the container into the garbage when it is full.
Grinder head maintenanceMove your grinder head up or down, as it is wears, to a new section. You should be able to get three or four sections out of a typical grinder head.