personally,
i like to get a stable install, with everything necessary but not everything desired
do a clonezilla of it and forget it
if you need to backup anything else, just drag and drop to a different drive/partition
perhaps you need to do more, then i'm sure something more complicated will work for you
actually i never bother backing up linux anything, it never fails (well, rarely, and never so i lose anything important, cause i use other drives)
i only use clonezilla for windows, cause it is so much more of a pain to reinstall, and i only use it for games, so i don't care if it fails either, just don't want to have to start over from scratch there
linux is rather fun to start over from scratch with, it is so easy and smooth and there is always some new version to try, anyways
but lm 13 has been going strong for a long time now
lm 14 is doing just fine as well, which i am using right now