In that case

I cannot fault Jonathan7's advice.

I'd also consider having a linux partition and multiple back up drives.

I've been in a position where a mac partition was on the fritz but I could restore it and access the data on it because the linux partition remained intact.

I've also lost the main drive and the back up before but the back up to the back up was untouched.

It's horrifying when this sort of thing happens and it happens very frequently to fan editors by the sound of things.