Some colors are more transparent than others. Some colors are very opaque. Test your colors on a separate piece of paper to see how they work together. Too many layers of crayon can make the colors resist each other. This can make it harder to add more color. Use as few colors as possible to get your end result.
How to Draw with Crayons Like a Boss. There's nothing more inspiring to me than buying and opening up a brand new box of Crayola crayons. I think anyone with an ounce of artistic ability fondly remembers coloring as a child. Just the word coloring makes me happy.