VNC Setup is Easy

Install x11vnc

sudo pacman -S --noconfirm x11vnc

Store VNC password to a file

x11vnc -storepasswd

By default this will store your password at ~/.vnc/passwd Add this command to your startup script

x11vnc -forever -rfbauth /home/[username]/.vnc/passwd

For Raspberry Pi

If the Raspberry Pi is headless, you may want to add the following lines to /boot/config.txt

hdmi_force_hotplug=1
hdmi_group=1
hdmi_mode=16