So, I have some nice tips for your .bashrc, with screenshots. Also a handy command to show your biggest packages in pacman/arch.
Simple Calendar with today marked as ##
Fast cd up:
Network Info (LAN IP, IP and MAC):
Biggest folders in directory Gigabyte version:

Biggest folders in directory Megabyte version:

Process Grep:

Nice greeting when opening a bash shell:

(put this one at the end of your .bashrc file)
And the huge packages finder:

(I've put this in /usr/bin/dup and chmodded it to 755).
Thanks to the arch forum for most of these tips!