Have you ever listened to your mix and thought its too narrow or that it lacks a good stereo field?
To compose an beyond the imagination stereo image, the soundstage needs to be wide and the mix has to sound well-founded in mono. This is one of the hardest things to do.
With that said the stereo spread should not be so distended that the image is unrealistic. The best way is to try and place each instrument as you would see them play live onstage from the view of the audience. For case in point instruments hard left and hard right. This goes mainly for guitars and drum toms.
Another way is to pan them form the drummer's point of feeling. The kick drum would be dead center, right in the middle of the mix. The snare drum would be
left of center and the hi-hat will be established somewhat to the left of the snare drum. You would place the toms and cymbals in every respect how they would appear on the drum set.
Then the guitars (electric and acoustic) can be panned at 10 and 2 o'clock. Then the vocals and bass guitar would be right up the seat. Background vocals would be placed just right
of mid. With this way, you have all your important information in the center and in mono and your supporting cast would be on the outside. Just remember,
this is not the only way to do it, as the stage can hold a wide variety of musicians that are playing instruments. There are no set rules, just like everything else
in mixing. So aside from where you place each instrument, it is very powerless to maintain an accurate representation of all the instruments.
Just keep in mind that when you pan instruments hard left and hard right, you can usher in phasing problems when the mix is played in mono or pseudo stereo.