Sit before your mixing board, and imagine an orchestra or a band on a stage in front of you, and you are the conductor.
Position the instruments as they would appear before you: to your left, to your right and in front of you. Drums, for example, are placed in the center, or just to the left and right of center as a drum set is set up; the same is true for vocals.
Position all single vocal elements in the center of the mix, loud enough to be heard over all the music. In a commercial, this is the announcer; in a music track, this is the lead vocal.
Balance the levels of the lead vocal or announcer with the entrance of any background vocals tracks. This is solely the training and experience of the producer, but is generally at the same level as the lead voice or vocal.
Add audio effects to as many channels as you want. Such "audio sweetening" as echo, compression and graphic equalization sonically alters an instrument or voice to make it more or less noticeable to a listener, or to add a sense of "liveness" to the track.
Make a final stereo mix once the mix or remix is to the point of being saved. Burn or save a final two-channel stereo version to a CD, or save the file in this form to a hard drive. Save the music in one of the popular digital formats: mp3, aiff or wma.