Until recently my tempered mixes were drying out all so quickly. Even with the porcelain palette with wells the mixes still dried quickly. Since I began adding lots of water my problem is over. I find it important to constantly swirl up the mix but that's no issue at all.
As a plus, these watery mixes allow for many glazes, each contributing slightly. I'm finding it much easier to build transitions. I did overdue the shading with umber before realizing that Chromium Green washed worked nicely as a complementary shade. This piece is proving to be a really great lesson.