what i do is set up all my guitars to be flat in the daw (no eq, no compression, no gate, no inserts), and send them all to a bus with c4 on it
i compress out some low mid energy that will muddy the mix, compress some super low end flab, and some high static frequencies
this will make the guitars loud and proud but not overcrowd the mix
i definately avoid pumping of the guitars, and make sure you're just getting rid of the areas that will create a problem in the specific mix (per song).
i am able to do this because i track guitars with the final tone to disk. if you had some problem with the tone, you would have to be fixing the guitar tone as well as helping the mix, which is a little different.
between a tube screamer, a high gain amp, any stereo bus comp you put on the mix, and any compression due to mastering, I try and keep high gain guitars as dry as possible.
Any other kind of tones I fuck with however I want to.