WoeUSB is a tool that lets you /very easily/ create a bootable USB with Windows in Linux. It works with only one command, so there’s not much to write about.
# woeusb --device windows.iso /dev/sdX
There’s also a GUI for it available via the command
woeusbgui, but we all know what I think about GUIs. :)
It’s available via AUR as woeusb and woeusb-git.
It’s available via WebUpd8’s PPA.