1) Isolate the body. Draw it alone, separated from other objects in the environment. Remember, however, that the environment continues to affect the body.

2) Draw only external forces that act on the body. If the body pushes on something else this force is drawn on that other object.

3) Every force you draw should be exerted by an external body that you can identify. (i.e.: You must be able to point to the the object that generates the force.)

4) Every force you draw should result from contact with some part of the system. (the object "feels " the system) "Action at a Distance' Forces are the only exceptions to this rule. In classical physics this only includes Gravity, Electricity and Magnetism .

5) A coordinate system showing the positive axis directions should be included in every F.B.D..

6) Each force should be given a descriptive variable name. It is a good idea at first to describe the force with a brief sentence. Ex: F is the force of the hand on the table.

7) When working problems in your homework involving several objects, remember that the action/reaction pair is the pipeline that carries information from the FBD of one object to the FBD of another