In short, here is the complete list to get the minimalistic Arch Linux with latest KDE Plasma minimum desktop environment. Note This is living post, therefore updates will be added in the future, mostly adding explanation with illustration/screenshots on each command.
Make sure to check if there is internet connection to the Internet . Do ping 8.8.8.8 to see.
Install our most favorite text editor of course pacman -S vim.
Check your disk structure fdisk -l and create partition by cfdisk /dev/sda. Check DOS instead of GPT if you don’t have existing Bootloader. If you have existing drive/partition which host Windows with UEFI, usually the bootloader is listed also with cfdisk.
Add propietary format to your existing partitions mkfs.ext4 /dev/sda*.
Enable memory swap if your system has less RAM (mine is 16GB and I do not have swap) mkswap /dev/sda*swap then swapon /dev/sda*swap.
Mount the root to the first partition mount /dev/sda1 /mnt.
Create the ~/ or home folder inside the root mkdir /mnt/home then mount the second partition to the home folder mount /dev/sda2/ /mnt/home.
Install the base and base-devel Arch Linux package to the system pacstrap /mnt base base-devel.
Generate genfstab file genfstab /mnt >> /mnt/etc/fstab.
Create root access on using bash shell arch-chroot /mnt /bin/bash.
Create locale.ge file vim /etc/locale.gen then enable it locale-gen.
Configure the language the system will use vim /etc/locale.conf and for me, I use generic English LANG=en_US.UTF-8.
Check all available zone infols /usr/share/zoneinfo and enable on your closest area ln -s /usr/share/zoneinfo/Europe/Stockholm.
Then sync the system clock to the area you’ve chosen hwclock --systoch --utc.
Setup password for the root passwd.
Add your computer name as the default hostname vim /etc/hostname and add [computername].
Make sure that DHCP is enabled when you opt so systemctl enable dhcpcd.
Before we boot, we must install the bootloader. For this we use GRUB pacman -S grub os-prober.
Tell GRUB what drive it should seek for the bootloader grub-install /dev/sda and create the config file grub-mkconfig -o /boot/grub/grub.cf.
Reboot the system sudo reboot.
Now, we gotta add new user (non root) and add it as sudoers. Open visudo, then uncomment # %wheel ALL=(ALL) ALL. It means, all members of wheel group will be able to be invoke bash with sudo access.
Add your new user useradd -m [username], and set its password passwd [username].
Add the user to the wheel group usermod -aG wheel [username]. Then reboot.
For me, I like KDE Plasma due to balance between simplicity, package repository, stability and also maturity. Some people might like Cinnamon for GUI, XFCE for light and robustness and many other. For me, I took sudo pacman -S plasma plasma-meta which will install the most minimum setup of KDE Plasma 5.x.x. Then install the desktop sudo pacman -S plasma-desktop.
Now, install necessary applications for KDE, e.g., browser, file explorer and simple text editor sudo pacman -S konsole dolphin firefox kate. For complete KDE applications, you can install all package by sudo pacman -S kde-applications but it will take around 2.5GB to install.
Install desktop manager for KDE, sudo pacman -S sddm and enable it sudo systemctl enable sddm.
Init sudo pacman -S xorg xorg-init before the last reboot, then restart sudo reboot and the you should be prompted with the first GUI KDE Plasma on Arch Linux.
Cheers.