I use ARCH btw

Following the guide is mostly ok ; A word on something that escaped me :

When you use a graphical installer, it will both assist in creating / deleting / reorganizing partitions, then at formatting them or not, 
then in assigning their roles as "root", "home", or "swap" and so on ; I never realized those where completely independent actions, and that you
can partition or not, format or not, and, assign partitions with fstab later on independently.

Frightening, or hilarious, side note : I know I installed my last system without running the fstab generation,
and the system build itself out of the /mnt/ ; /mnt/home and /mnt/swap partitions from the live system 0,0

Contents 1 Yes, but 2 Default install through pacstrap needs a lot more stuff, you'll probably want 3 don't forget to enable some systemd services, duh 4 And make a basic user 5 AND IF YOU FAIL...

Yes, but

- No need to partition if there's no need to! (esp EFI) You'll run into a permissions nightmare on your /home, but that's better than loosing data :

 When the /home partition is mounted to /mnt/home at 'pacstrap' time, just chmod -r 777 the entire contents of the previous /home folder ; 
 when you make your new user, be sure to give it another name.

- Only format your system / partition (or root partition) with makefs.<type of filesystem>.

- It's ok to mount the EFI partition to /boot/efi and not simply /boot so as to not fill that small partition with everything in /boot, especially numerous kernels

 On my fresh install, the EFI partition is 260MB which is a factory default - and my /boot partition is already 268MB ; 
 ergo, it wouldn't fit, with just 4 kernels + the windows stub

Default install through pacstrap needs a lot more stuff, you'll probably want

- base-devel linux-lts os-prober pacman-contrib

- grep rsync nano tar git iwd - snapper ?

- gdm gnome networkmamager gedit - or any of your login manager and desktop environment of choice

- bluez bluez-utils usbutils

- firefox vlc smplayer gimp

When you chroot in, it's normal for os-prober to not see the M$ partition, even if it is mounted ; you should re-run it, and re-run grub-mkconfig, when you did reboot into the actual, fresh system.

don't forget to enable some systemd services, duh

- gdm.service

- NetworkManager.service

- bluetooth.service

with

 systemctl enable <name of unit>.service

If you are already in your graphic environment and instead need it to be enabled and start immediately (like for network), run

 systemctl enable --now <name of unit>.service

And make a basic user

Then create a basic user with

   useradd -m <name of user>

Add it to sudoers with

   EDITOR=nano visudo

Now you can reboot. Have you installed some network software? Have you enabled a graphic shell ? That's the core needs for a functional, fresh install to be tuned further as needed.

Set up aur or install flatpak for dropbox and ungoogled-chromium ; add python-gpgme for dropbox.

Good luck with btrfs, and snapper, and snap-pac, and grub-btrfs, and don't forget to hack mkinitcpio as described.

AND IF YOU FAIL...

 Just re-do the whole install thing ; it is better to loose 20 minutes re-doing it than spending 20 days fixing it