This is only FWIW.

After some time testing various backup techniques, involving everything from Retrospect to TimeMachine, here’s where I’ve landed. This is only best for me… what is best for you is what WORKS for you, and what you’ll actually -use.-

I use SuperDuper to keep clones of my various volumes. I have my main boot drive; a “hold” volume and a “work” volume (these last two happen to be on the same physical 1TB drive. These are also kept as clones. The boot drive is cloned once a day; once a week; and once a month to different removable drives. Data which changes frequently (such as my programming, video editing, and client projects) is kept on the “work” volume, and data which changes seldom is kept on the “hold” volume.
 
I have a 1.5TB drive mounted internally as my running backup drive; and yet another as my “cache” drive.  This last is for Photoshop caches, as well as FCP; EyeTV; scanner output; and all other temporary files. (It’s actually divided into different volumes to further refine this workflow.)
 
The larger 1.5TB “backup” drive is handled by Chronosync. After much mucking about with TimeMachine, DataBackup, and so on, I landed on Chronosync because it can be very granular, with all the control I’ll ever need.
 
For example, “work” contains things which I’m working on, and which I want an hourly backup. It also has things that only really need to be backed up once a day. Some things I want archived with a history trail liked TimeMachine, while others only need a couple of archives, or even none.
 
Equally, on the boot drive, which is mostly cloned by SuperDuper, there are a folder or two which change several times during the day, and I’d like to have them backed up every couple of hours.
 
Chronosync handles all this with aplomb. It lets me schedule specific times for backups, in all kinds of various ways. My programming, for example, has hourly backups that will go back 20 archived changes – (at a minimum – two days;  twice as long as TimeMachine.) There are daily and weeklies of these too, up to 1/2 year.
 
I also have a dozen other removable drives that serve to hold infrequent and/or long term backup of various files and folders, such as my photography. I’ve got Chronosync set to automatically update these whenever they are mounted, with my specified settings. Stick the drive in, and it updates.
 
The clones and off-site stuff I have to remember to do myself, but the Chronosync stuff is all automatic.
Of course, Chronosync is not as simple to set up as TimeMachine, but once you understand it, a new sync document is quick and easy to create, and from then on, it requires no attention at all (other than a check now and then to make sure your destination volume(s) are in good shape.)
 
Some of this backup workflow is old and venerable; some of it is fairly new.  If any of it turns out to be less than satisfactory, I’ll report back here…
FWIW.
HTH.