Howto `debootstrap` a bare minimal Debian Desktop from scratch

partitioning and filesystem
create a root partition and swap partition
mkfs.ext4 and mkswap
run debootstrap
debootstrap bullseye /mnt/ http://ftp.de.debian.org/debian
bind mound dev proc and sys
for m in dev proc sys ; do mount /$m /mnt/$m ; done
chroot into the new environment and run bash
chroot /mnt/ /bin/bash
give the machine a good hostname
echo mycrazyhostname > /etc/hostname
install basic stuff, like linux kernel, grub and networking-scripts
apt update ; apt install linux-image-generic grub-pc ifupdown man console-data locales
do locales settings
dpkg-reconfigure locales
configure keyboard
dpkg-reconfigure keyboard-configuration
install X-Server and window manager
apt install --no-install-recommends xserver-xorg jwm xdm xterm
ensure grub is installed
grub-install /dev/sdXY ; update-grub
set root password
passwd root
create a user
adduser coolusername
create fstab with content
/dev/sdXY / ext4 defaults 0 1
exit chroot and reboot

Howto debootstrap a bare minimal Debian Desktop from scratch