When I'm faced with hundreds of pieces to glaze, even a limited palette of glazes can create an overwhelming -- even paralyzing -- number of glaze combinations from which to choose.
I've often spent literally hours deciding how to glaze what actually only took me that same amount of hours to glaze. Just deciding how to glaze the pieces was (and always is) half the battle.
Here's a nifty trick I came up with.
First, I photographed the piece(s) against a strongly contrasting backdrop that would be easy to make disappear in photoshop. Next, I do the photoshopping -- erase the background and bring up the contrast and maybe tone down any color saturation so that I'm left with just the basic shadows and shape of the piece.
Next, I copy the photo multiple times per sheet to give me plenty of blanks to experiment with, and I print those sheets on white paper.
Finally, with transparent watercolor pens, I can color the pieces and give myself a really good idea of what the finished pieces will look like. The transparent watercolor pens allow the shadows in the photographs to still show through so that the 3-D effect of the pot is not lost in the coloring. That shadowing also keeps the color from appearing as flat paint, thereby giving a more true preview of the fired end result.