In this video I talk about a guideline that I follow for every mix that I do. When thinking about all the sound elements I think about them in a X,Y,Z axis.
The Z axis represents the level (or volume) of each sound. As you know sounds with a louder level will appear to be closer to the listener and sounds with a lower level will appear to be farther from the listener.
The X axis represents the frequency range. When mixing I make decisions on which sounds will occupy which frequency ranges. For example since I know that the bass, 808 or kicks will occupy the low-end then I remove the low-end frequencies in all other instruments to reserve that space exclusively for the low-end instruments.
The Y axis represents the stereo field. To keep a good balance I keep some instruments centered, some spread halfway across and some wide spread.
Another tip that really helped me was to focus on mixing a difficult record which contained many tracks. I would attempt to mix the record many times, often starting over. This is because it forced me to find solutions to problems that I would encounter in the future. I knew that if I was able to get a good mix from this song then mixing any other songs would be a lot easier.
These are a few important things that have helped me to improve my mixes. I am confident that they will help you if your ready to put in the work.