Here is another tip I recently discovered.
In cleaning up after several days of painting, I discovered that Mr. Clean's magic sponge makes it easy to get my palette knives back to shiny new and works well on the dried gunk that ends up around my brush cleaning jar and the edges of my palette. I use a razor blade scraper and "Simple Green" spray cleaner on the palette itself, then wipe clean with paper towels. The Magic Sponge works nicely if you get a bit of oil paint on your hand, too, although repeated scrubbing does tend to chap the skin, so if you have a lot of paint to remove, use baby oil and then soap. (Usually I wear latex gloves to paint, but sometimes I get lazy, or I pick up a dirty rag or paper towel. And my brush handles have been known to get messy, too.)
Always be sure you have plenty of ventilation in your studio. I have a box fan in one window that I use to exhaust the air, and another in a different window that sucks in fresh air. I also have an air purifier but I know that eventually I will have to upgrade to one of the ones made specifically for artists. At least the air quality is better than that I experienced in art school.