Concentrate on the basics. If you are just starting to color, keep things simple. Forget shading, burnishing, details and texture _ start off by block coloring and concentrating on keeping between the lines. Block coloring is simply the practice of taking your colored pencil and filling an area completely and evenly with that color. Get to know your pencil, feel the weight of it and practice control. Simply filling those spaces with color whilst trying not to go beyond the lines will help you master control and prime you for learning more advanced techniques.
Crayon Tinting. Using crayons for tinting embroidery is the most common technique. It's easy to learn and most people have at least a few crayons around. Crayons produce a bold color, but you can also work more gently with them, resulting in a lighter tint. Just like coloring on paper with crayons, varying the amount of pressure and layering your coloring creates some very cool shading. That shading gives your embroidery texture and dimension, and it's fun to use with modern or vintage designs.