The following may seem like a no-brainer, but many times a simple change can make a big difference. I’ve seen quite a few students struggle needlessly before learning the following.
Get organized! It’s a good idea to organize your palette colors in an order that makes sense to you. And always keep them in that order. This way you won’t have to scan your palette mid-stroke wondering, “where did I squeeze out my pile of yellow this time?” You’ll get used to the location of each color and it will become automatic to reach for the color you need.
Of course, this requires that you stick with a certain “usual palette” of colors. At least for a good period of time. It takes awhile to become familiar enough with how each of your chosen palette colors works with the others. If you’re always squeezing out random colors for each new painting, you may never get familiar enough with how colors work together.
My full palette has 13 colors, but now that I know what they all can do, I often use fewer colors — a limited palette — for different color effects. (But the paint piles remain in their usual locations on my palette.)
So choose your colors and decide how best to organize them. Painting is difficult enough as it is. Make things easier on yourself!