Time Machine Strategy? I just finished a tough weekend of getting my Mac back. 
For whatever reason, it would no longer boot. I am running 10.6.8 on a 2010 MacPro.

I installed a new copy of the OS, and migrated, then updated the OS, and it froze. Back to the install disks, loaded, updated OS first via software update, then migrated and I'm back in action. 

The migration took hours as the drive had a lot of data including large iTunes files, etc. 3TB drive is my main drive. 

Is there a better strategy for one's OS drive and data files that would make a re-build less time consuming? e.g. Use the OS drive, and keep it smaller, say 1TB, just for the OS and apps, and then a second drive for data only? 

I'm grateful Time Machine worked so well, just looking for a faster way to get going next time. 

(Note - I have too many apps needing Rosetta to jump to 10.10 full time. Not ready to drop $hundreds on updated software.)
If you have a 3tb drive would you not partition it? 1tb would be HUGE for OS and apps, I can't imagine the number of apps you'd need to fill that much space. Do remember though, that you'd still need to backup your data (SuperDuper and Carbon Copy Cloner are sometimes more useful for data backup). As you have a MacPro then dropping a new, smaller boot drive in should be very simple and then you could use your 3tb drive just for data (iTunes etc). You might also think of a smallish ssd as a main boot drive (even 128gb is probably fine for all the OS and Apps you'd throw at it). This would boot very fast and apps also load a lot faster.