"Mixing Flesh Tones"
I prefer to use glass for my palette, though it is not without problems.
When mixing up my colors, I set the glass on a white paper towel (very high-tech), though I am thinking about switching to a medium grey, since my midtones have a tendency to be too light.
At the end of a painting session, I put the palette in the refrigerator, covered by "Press'nSeal" until the next time. This works great; in fact, I came home from 10 days in WV to still fresh paint. Until I broke the palette. (Reminder, cold glass is very fragile.)
I buy old frames at yard sales, cut down the frames to reuse, and save the glass for palettes. If necessary, I will also cut down the glass, but the cut edges need to be taped; they're sharp!
Theoretically I could clean off the glass, but usually I dump it in an old pizza box when the paint is gone.