The Dreaded Dirty Palette
There's nothing worse than having a fantastic idea for a watercolor painting and wanting to begin right away, then you open up your palette and it is dirty!
If it's really dirty and messy, you gotta spend time cleaning it up. It could take a while and if you only have a short amount of time to paint, you will end up spending most of it cleaning up your palette. You can't paint a quick, bright, beautiful painting with a sloppy muddy palette.
For me, the yellow is always the dirtiest.
When you're done painting for the day, clean up your palette. Wipe out the mixing area with a damp paper towel or a sea sponge. Take a damp flat watercolor brush and swipe off the tops of the paint wells.
The next time you go to paint, you will be ready to go with a clean palette.