Being a curious newbie, i've been reinstalling the os a dozen of times even since i started using Linux. Luckily i keep a seperate /home and also backup 'achieves' from /var/cache/apt to reinstall from synaptic manager, so it doesn't take as much time to setup the system as it used to. But, it still takes a lot of time.

Should i create more partitions for /usr, /var n such? Which partitions need to be formatted when install a new system? ( cuz i tried reinstalling without formatting the hard drive once, but it doesn't help : i.e. sudoers or grub still have problem etc. n to a newbie like me, fixing those takes more time than reinstalling the os )

Asides from /var/cache/apt/achieves, are there any other folders i should backup? cuz it looks like it's not enough. When i add downloaded packages from synaptic, it still needs to download a lot of other packages, and after that, i still have to download some programs from Software Manager, then run Mint update again. ( but with less things need to be updated though )

So can you give me some tips about partitioning n backuping?