Soundtrack production is an art, but it is an art one can learn. Of course, it is no easy task to create a superb narration, but short, informative comments are often very helpful for the viewer. Whatever narration there is should sound natural, expressive and spontaneous, not wooden or stiff.
A general rule applicable to all commentary is that less is more. Pictures should speak for themselves, and things that are evident to viewers from the pictures require no comment.
Spoken commentary should be mixed with both the original sounds and the music in such a way that the original sounds can still be heard. Natural sound is part of your video footage and should not be cut away altogether if at all possible, because video without natural sound can easily seem sterile and lacking in authenticity. Frequently, however, the recording equipment captures noises from aircraft and cars that do not appear in the scene later. Sounds such as these, or loud wind noises, which can be distracting or annoying, should be masked, filtered or replaced with appropriate narration or music.
Appropriate music adds a professional finishing touch to your movie and can do a lot to reinforce the message of a video. The music selected, however, should always be appropriate to the message of the film. This is sometimes a time-consuming matter and a challenge, but greatly appreciated by the viewer.