When you draw something that you are looking at, that is observational drawing. It is not from your imagination or memory.
Your goal is to draw what you are observing in three dimensions so that the result looks realistic on a flat, two-dimensional surface such as a piece of paper. Your observational drawing skills can be developed. Carefully observing or learning to really see your subject is an important first step to drawing well.
Praying Hands, Albrecht Durer
CONTOUR DRAWING
A contour is the line that defines a form or edge - as an outline.
Your eye and hand must work together, slowly, to follow the visible edges of your subject. You look at your subject , not on your paper as you draw. Contours describe the outside and inside edges of a form. A finished contour drawing has no shading and appears as an outline drawing. Sometimes the line is one continuous line, drawn without lifting your pencil off the paper
SHADING TECHNIQUES
In order to make your drawn subjects appear more 3 dimensional, adding shading in a range of values, light to dark, will enhance your observational drawing, showing that your subject has volume.
It is essential that you identify where your light source is. That will determine where to place your tonal values on your subject(s) and where to add your shadows and highlights.
HATCHING TECHNIQUES
The basic types of shading depends on how you apply your pencil strokes. Shading or hatching techniques include : hatching , cross hatching and contour hatching, stippling (Pointillism) and scumbling/scribbling .
NO SMUDGING is required when hatching in pencil.
Using hatched pencil strokes can also emphasize or mimic the texture of your subject as well as create value.
Stippling
Pillows drawn by Albrecht Durer
To create a range of values, shade with your pencil using more or less pressure, pay attention to the number pencil you use (H= lighter, B= darker, softer lead), and employ hatching techniques as you shade in the direction of the form.
COLOR PENCIL TECHNIQUES
Using color pencils allows you to create dimension while mimicking the hues, or colors of your subjects. Since it is impossible to have every color you see represented by a specific color pencil you must visually"mix" your colors to create all the colors you see in your subjects. Unlike painting, where you actually mix colors, using color pencils requires that you LAYER your colors, building shaded layer of a color over another to create new hues.