This customization was designed for Arch Linux but can be easily adapted to any distribution.
Some packages are required to install successfully, for that see the xfce4-packages
file.
# Clone this repository.
$ git clone https://github.com/bebetoalves/minimal-xfce4-theming
# Enter the directory.
$ cd minimal-xfce4-theming
# Run install script.
$ ./install.sh
After installation, reboot your system.