Just curious, what sort of destructive processing do you do to your audio before you begin to mix? And what is your forethought during that process to achieve the low end mass you're aiming for? Do you sometimes low-pass things differently depending on the track or do you have a set range of freqs you carve out first and foremost?
The best thing in the world is having a great sounding mix the minute you push up faders. To get that you need to record your tracks in a way that they fit together, without a lot of fixing or shaping to do in the mix phase. I record guitars generally with plenty of midrange, rolling off the rumble. Bass guitar is recorded with extra low frequencies. I check phase carefully and sum drum mics in advance to avoid phasing struggles later in the mix. I record an extra sub mic on the kick. I record the overdubs instruments in pairs, often to give the vocals a place in the middle of the mix later.
Where I do most of my mix work is in the stereo buss compressor and stereo buss EQ. I'll use reference material to help steer the overall sound of the song I'm working on. I usually place the stereo EQ first, with the compressor following. I'll adjust the stereo compressor to give the drums some snap and mush everything together. The stereo EQ will add the "air" on the very top.
When mixing, if you are not fighting with your individual tracks, you have freedom to work on delay throw effects, filtering, dynamics, panning and fun stuff!