You are using a literal "picture plane" for your next projects. Your first assignment using the picture plane is to draw your hand. Please read below and follow the steps I have listed.
Fig. 3 The line drawing has been traced to the paper using pencil
Step 4: Now tone the entire composition using the side of your pencil lead. After you tone the entire composition area, use a paper towel or Kleenex to blend all your pencil shading. You should notice that everything evens out to a fairly equal tone. (If your drawing was too light to begin with then this is the step where you will notice it disappearing as you blend with the paper towel. )
Fig. 4 Tone the entire composition with graphite and then blend with a paper towel
Step:5 You are now ready to begin "removing" the highlights. At this point you will need to first do two things: 1) tape your paper to the table top so that it won't move while you work and 2) get your hand back into the exact position it was in earlier for your Picture Plane tracing. Now look closely at any area that has light touching it. Think of your toned paper as the middle value and anything lighter that should be erased slightly. Be careful not to completely erase your contour lines; you are simply showing which parts of your hand have light hitting them. You may also show where the light hits the background like in the example below.
Fig. 5 Show highlights by carefully erasing the light areas of your hand and background
Step 6: The last step is to now add all the darker shadows in the appropriate areas. This is why it is important to keep your free hand in the same position that you selected earlier. You must look carefully at every detail on your hand. Ask yourselves "Which wrinkles appear to be the darkest?" "Where are the shadows/highlights on my fingers?" "Does my shading look accurate to what is really on my hand?" This is the final step and the point in which you should do your most diligent work. Take your time, work carefully and stand back when your finished to see how you did. I want to see that you spent time on this - not that you rushed through it on Tuesday night.