I have created a one-liner to install XFCE on Arch Linux, Raspberry Pi. Find it in the last line. I wrote about installing XFCE on Arch Linux running on Raspberry Pi but it seems that those instructions are no longer valid for the new version of Arch as hosted on Raspberry Pi download page. So below are the new instructions for installing XFCE on Arch, Raspberry Pi. Please note that initial steps are similar for the previous versions of Arch too.