Well this may sound strange, but I think some of the best tracks (not mine!!) ever recorded turned out as well as they did because they were mixed from the very beginning - sometimes as early as while they were being written.
Please note, I didn't say ALL the best tracks, nor do I mean to suggest that waiting till tracking is completed will always result in a poor mix - some truly amazing tracks have been recorded with both approaches, but for me, having the final mix in mind has always worked better.
How can that be?
I walked into my first recording studio in 1974, it was an 8 track studio, and for the time it was a very well equipped 8 track studio, they had two Urei compressors (probably LA-3, maybe LA-4) and one Urei 1176 and two Orban Parasound equalizers. While I was working there they added a second 1176 and a pair of dBX 160s. They also had a spring reverb (I think it was also an Orban) and an EMT plate. The 8 track was a Teac 80-8, and they mixed to an Ampex AG-440, might have even been a 350, my memory is a little blurry. The mixer was, I think, a Mother's Finest Audio - can't remember the exact name, they were made in the Philadelphia area by former RCA engineers. It had a simple 2 or 3 band EQ on each channel, I think there were 16 inputs and 8 busses and a 2-Mix.
Anyway, that was where I started to learn the craft. Every studio that I worked in from then till the mid 1980s was, at best, an 8 track studio with similar gear. Eventually I stumbled into a 16 track studio and thought I'd found heaven, but alas all that really did was let us do more stuff in stereo.
What did I learn, and why do I still work this way (sorta)?
The first thing we would do was sit with the musicians and plan the recording. What instruments, how many vocal tracks, what, it any, effects - pretty much a road map. We'd take detours, of course, but we always started with a map.
So we'd know if we wanted the drums in mono or stereo, and we'd know there would be this or that so that the drums would need to be pre-mixed accordingly. I really can't recall a single session where we did not end up bouncing the drums down to two, or sometimes one tape track, so we had to have an idea of what the final mix would sound like - we could make minor changes to the drum mix later, but we could not change the balance dramatically, nor could we remove a drum.
At which point we had six empty (?) tracks. We'd do the same thing for the rest of the rhythm section, we'd bounce guitars, bass, and keyboards down to a stereo pair, so all panning decisions and basic balance had to be made right there. Sometimes, for musical or scheduling reasons we'd record the entire rhythm section together (I always preferred that). So we'd have to really pre-mix the drums, like in the mixer. That was a challenge, but the performance always seemed ever so slightly better, so we did it.
Now we had four tracks left for vocals, and we'd end up bouncing down the background vocals a couple times. At which point we would have:
one stereo pair for drums
one stereo pair for the rest of the rhythm section
one stereo pair for the background vox
one track for the lead vocal
one track for whatever else we wanted
If we had horns we'd end up bouncing the entire rhythm section down to a stereo pair to free up a stereo pair for the horns. And if we were doing anything remotely different we might have to work with mono tracks for the drums or even the entire rhythm section.
Needless to say there was some stress involved.
When we moved to 16 tracks things became somewhat easier. A typical (as I recall anyway) session might be mapped out something like this:
1) Bass
2) drum overheads L
3) snare/hat
4) drum overheads R
5) lead guitar
6) acoustic guitar
7) keyboard mix L
8) keyboard mix R
9) hand percussion
10) lead vocal
11) rhythm guitar
12) background vox L
13) background vox R
14) piano L
15) piano R
16) Bass drum
You can see that we had the ability to push off some decisions till much further down the road, and that was kind of cool, but we still had this discipline of thinking ahead firmly ingrained, so we tended to think that way even with the extra tracks. And there were lots of different version of that - sometimes the drum overhead was mono, sometimes all the keys were pre-mixed, sometimes the piano was mono, sometimes the rhythm guitar was stereo, and so on. But it was a big leap.
I still think that way today, even though I have, for all intents and purposes, infinite tracks and infinite processors and effects. The effort to plan things out keeps my mind on the right path, I think.
I've made some minor tweaks so that I can make major changes at mixdown time - I'm not a idiot<G>!
I still print all my processing and effects while tracking, but I keep the unprocessed tracks too. So if I change my mind I can swap out one phase shifter for another, or re-equalize or whatever I need to do.
It's kind of the best of both worlds! And I apply all my processing and effects to live and MIDI or VI tracks.
How can this help?
For one, I'm always thinking about the mix, how different instruments will fit in to the final mix. I find that really helpful.
For another, at mix time the only thing I need to do (in theory anyway) is ride levels and add the final reverb. Believe it or not, sometimes that really happens.
Give it a try, I think you'll find that with a little practice it not only makes mixing easier, but it also makes the structure of the song stronger.