If you're mixing something someone sent you 9 times out of 10 you're SOL and have to do the time reorganizing everything to the way you want it. We all do things a little bit different.
If you're doing the tracking start with a game plan. I literally write out every track I plan on doing on a piece of paper labeled 1-24 or whatever. 1 kick out 2 kick in 3 snare top 4 snare bottom...etc
Talk to the band and find out simple arrangement things. How many guitar parts, are they doing leads and solos separate, any parts with delay or reverb, is there any aux percussion like shakers or tambourines, are there backup vocals, harmony tracks, etc.
Find this out for every song and get a "worst case" scenario with the most tracks they could ever need and then make a template for the session so for every new song you just click it and open it and boom, ready to record, no setting up. Instead of "saving as" you just "save as template" and save it in the bands folder on your HD. From then on, whenever you're ready for the next song you double click the template and it pulls up the full session ready to record.
That alone saves me hours in 8-14 song sessions.
It's also a great idea to create tons of groups. Grouping makes me so damn happy.
Also writing down the levels and settings on EQs and compressors really helps me out. Once you have one song 95% mixed, you can pretty much copy the settings on every song and make the minor tweaks that the individual songs need. At the end of the day its still the same drum kit, bass, singer, etc playing at pretty much the same volume.
And finally, try to mix as much as possible while you are tracking. Get finished sounds going in, you know? I've always found less is more. Not every channel needs an EQ and compressor. Most of my mixing, organizational, and workflow techniques come in to play during tracking. Usually once you're trying to do BIG things during the mix its too late. Just remember it will always be music, focus on making it sound like it.
Like I said though, if you're mixing what other people tracked...