How to mix a song:

First listen to the tracks and decide which style you want to go. Try to see what you hear, get a vision. And mix accordingly. I took one of the most classical examples: The last supper. What do you see? The most important thing is in the middle. What's in the front is bigger than what's in the back, it is higher, deeper, clearer, wider and has more dynamics,has got more definition, than what's in the back. So in the back things are going to have less of everything: less volume, less dynamics, less panning, less base, less high. You see a room. Let's hear some ambient. This classical composition has 2 groups of 3 people on ech side. Maybe you prefer a different aproach and create some inbalance between left and right. But you could also discover some dialog going on on the right, while the guys on the left are more holding back. Now you virtually get a 3D impression and create depth. And if you look more carefully, you will discover even more details. You can see that the guitar player is hard panned right. :)

Don't ask me why , for the last supper, there is no food on the plates.

And if all this is not inspiring you, find another painting that does.

Eliminate everything which isn't needed to tell your story. Highlight everything that does help the song, the motion.

Music is not a frozen frame, When you watch movies you have to think about mixing and when you mix you should think about movies. Search for elements that pushes you to the chorus. Search for elements that guide you trough the verse. Make an energetic distinction between the chorus and the verse. Do something with the bridge. If the beginning of a movie doesn't catch your attention, you will loose interest and switch channels. Why wouldn't someone do the same with a song?