not withstanding all the other great comments here.....but I'd like to mention something that has helped me incredibly.......the use of a 'spectrum analyser'.
I've got a hardware type by kenwood, with beautiful blue fluro, hi-resolution, 'micro'-stepped display, and it's real fast!! (don't like the software ones!!)
I send a nice recording (some one else's, lol) thru that and watch the frequency lights dance, study them during differing parts and movements of the music.
I try to emulate that 'dancing' thru my own, similar program via mix/eq control. I can switch it to particular tracks, or use it to 'look' at my program.
Not that i would only trust a bloody spectrum over my monitors, but as an added feature, I'm finding my mixes are cutting it within 2-3 takes, (not 10-15 like before!!)
PS...my analyser signal is coming straight from the 'master out' of my desk, just prior to going back into my Delta 44.....works for me!!
Kindest Regards,
SS