A Variety of Pressure Creates Emphasis. If there are some areas you want to accent, you can press a little harder on the crayon and end up with a darker, more intense color. This is another good reason to color lightly for full coverage. For example, in this picture of the heart below, I pressed harder when tracing the lines within the heart and in the vein and artery openings. I did the same thing when coloring the muscles and the brain.
For a much lighter effect, you can mix a small amount of soft pastel with baby powder and apply it with cotton balls. This technique is usually used for gradient backgrounds. Lastly, enjoy your work! You can keep it in your portfolio folder or hang it on your wall. There are still a lot of ways to use coloring materials in order to give life to your drawings. Just don't be afraid to explore.