• pacman -S xorg-server xorg-xinit xorg-utils xorg-server-utils xterm
• pacman -S virtualbox-archlinux-additions
• modprobe -a vboxguest vboxsf vboxvideo

Редактируем /etc/rc.conf

MODULES=(… vboxguest vboxsf vboxvideo)

• pacman -S gnome gnome-extra gdm
• pacman -S gnome-tweak-tool

Variable $XDG_CONFIG_HOME is usually set to ~/.config

${XDG_CONFIG_HOME}/gtk-3.0/settings.ini
  [Settings]
  gtk-theme-name = Adwaita
  gtk-fallback-icon-theme = gnome
  # next option is applicable only if selected theme supports it
  gtk-application-prefer-dark-theme = true
  # set font name and dimension
  gtk-font-name = Sans 10

• gsettings set org.gnome.nautilus.preferences always-use-location-entry true
• gsettings set org.gnome.shell.clock show-date true

Подробнее

pacman