I'm new to Kali on Raspberry Pi and figured out some basic post-installation steps that will hopefully save a others some time.

Kali Linux RaspberryPi 2 (v1.2), 3 and 4 64-Bit, 2019.4
Specifically: https://images.offensive-security.co...xmon-64.img.xz

Raspberry Pi 4B, wired ethernet networking, USB wired keyboard and mouse, HDMI 0 connected to desktop monitor. After the usual write image to micro-SD card steps, the system has booted, and is at the desktop "greeter" screen.

Stop at the initial GUI login screen. Look up and to the right and select the correct locale/language from the drop-down. Otherwise it defaults to aa_DJ.utf8 - which is probably not what you want and will make some things look odd. For example, I selected "American English - United States" which changes it to en_US.utf8. Then login with the default Kali credentials, and once the desktop has loaded open a root terminal.

Set your desired LANG and LANGUAGE variables. For example:
root@kali:~# localectl set-locale LANG=en_US.UTF-8
root@kali:~# localectl set-locale LANGUAGE=en_US

Set your desired timezone. For example:
root@kali:~# rm /etc/localtime
root@kali:~# ln -s /usr/share/zoneinfo/US/Central /etc/localtime

On first boot, I got an unpleasant flickering default display setup with a large black border around the entire display.

To fix this edit /boot/config.txt

Uncomment this line near the top to get rid of the black borders:
disable_overscan=1

Then toward the bottom there is a second "[pi4]" block that isn't commented (again, this is for a Pi4). In this block uncomment:
dtoverlay=vc4-fkms-v3d
max_framebuffers=2

Reboot. With these basic changes in place things should look better and it will be nicer to move on to updates and tool installs.