If you want to do these stuff manually just like I do:
Always keep your sources up to date using:
sudo apt-get update
sudo apt-get upgrade regularly to upgrade all packages to newer versions, get security updates and patches.
sudo apt-get dist-upgrade
to get install new kernel, it might remove or install new packages if it was necessary.
time to time use:
sudo apt-get autoclean
to clear your
apt cache, it removes old
deb files which are not necessary anymore.
sudo apt-get autoremove
to remove old kernels or packages that are not necessary anymore like dependencies which are not being used anymore.
that's what I do.
If you use
apt instead of
apt-get then by running
apt upgrade you get all packages updates also new kernel and you don't even have to run
apt autoclean cause it's not going to cache
You should also have backup from your system's important paths:
are the places which I always keep a backup of them.