One thing that cannot be overlooked in machinima (or anything cinematic for that matter), is the camera work. Cinematography, placement, kinetics, all must be considered in your machinima as you film it.
Every shot is in essence the amount of subject being presented to your audience. The frame acts a a window. The composition of this frame defines the arrangement of the subject. Since it may be hard to describe in words all aspects of composition, I've compiled these images to help illustrate. Read it thoroughly.