Best Practice

I've been using Acronis since TIH 2009. I just recently purchased TIH 2013 for my wife's new PC and would like to know what is the best practice in making a backup.

Whenever I back up the HDD on my Win XP PC, I always use two methods:

(1) I switch on the PC, wait for bootup, launch Acronis, then backup to external USB drive.

(2) I change the BIOS to boot from CD, insert latest Recovery Disk that I downloaded from Acronis' website, reboot computer to launch Acronis from CD, then backup HDD to external USB drive.

So I *always* have two different .tib files on the USB drive.

Which method is best and why?

I did a test recovery using both .tib files and they both seem to work. Please understand that I don't have time to do a thorough test, so I'd like to know what is best practice and the technical reason why it is best.

Thank you, Team!