I have a Mac Mini, my main work machine and an MBP, used when I travel. I backup both my Mini and my MBP to Lacie Thunderbolt SSD drives using Carbon Copy Cloner which kicks off the backup procedure every night.
I also backup my photos, documents to both iCloud and DropBox.
I don't use iTunes on my MBP, my Mini is connected to another external SSD which serves as my iTunes disk that is also backed up.
Whenever I travel, I just sync my MBP to be update with my Mac Mini.
I am also looking at using iDrive backup [1], but have not done so.