Panning can help separate those competing frequencies.  Make it wide if it works in the song.

Don't forget shelf setting in EQ nodes. You can lower a range evenly. Try that on the guitar maybe.

I'm not sure if this applies, but logically I would think that side chain compression might help, Chevy.  That way you could limit some of the tracks behind--ducking subtly--as others peak without too much impact on the overall arrangement.  Naturally the acoustic environment for monitoring is the first step, otherwise any adjustments you make by ear won't be true.

Also, psycho-acoustically the fundamental of a note doesn't have to be present. It can be EQ'd out and the brain fills it in by using the notes' harmonics. I would think you could HPF the guitar and just let the bass/drums provide all that low frequency content. The guitar will still be "heard" playing those low notes.

Sometimes the mixing desk becomes a battlefield triage tent. Who's most likely to punch you in the face, the drummer or the bass player? You can only save one of them, the other has to die.
 
Start with the string part. It'll survive the most high-pass filtering. Then analyze the frequency spectra of the toms and bass (I like to use MMultiAnalyzer for this). You'll likely find that it's just within a certain band that they're conflicting. You'll have to experiment to determine which can better tolerate giving up that band.
 
If all else fails, use sidechain compression to let one dominate the other.
 
 

Guitarhacker
Words to live and mix by:
 
Nothing is sacred.
 
Less is More.
 
 
Short explanation:  Everything in a song can be cut, edited, removed, changed... not much is carved in stone and use only what you really, really, need to use to accomplish the goal.  Then re-assess and reapply the rules previously stated.

Yeah, Jimmy Page did not NEED all those guitar tracks.

Who's Jimmy Page? Oh a musician? oh ok

Lord Tim has the right idea and it is all about the arrangement first and foremost and I mean what are the parts actually saying. I bet too may parts are overlapping each other instead of weaving in and out of each other.
 
EQ and compression and stuff are all poor relations to actually sorting out the arrangement. What a great producer does is cut the music around a lot. I bet I could cut the parts up in such a way that the same phrases and intentions are applied but instead hardly anything is overlapping or playing at the same time.
 
You can be too precious about what you have played. If you handed this section over to a top producer the first thing they would be doing is removing unwanted overlapping stuff. You need to create the air and see what I have called the black backdrop behind the music. If you cannot see the black backdrop or it becomes a grey wash type of backdrop you have simply got too much going on.
 
When you get this stuff right you can actually have solid EQ and much more fuller sounding parts that have much more weight and body to them. Hacking out stuff EQ wise to make things audible is a poor way to do it. You end up with thin sounding parts.

Jeff Evans
You need to create the air and see what I have called the black backdrop behind the music.

My backdrop is fingerprinted using rainbow colors and jelly beans.

bitflipper
Sometimes the mixing desk becomes a battlefield triage tent. Who's most likely to punch you in the face, the drummer or the bass player? You can only save one of them, the other has to die.
 

 
Yikes!  Ed...we better lie LOW for a while.
 
(See what I did there!)
 
 
 
Arrangement is key.  Less clutter.