1 - Using the last official Raspbian Buster Lite from https://www.raspberrypi.org/downloads/raspbian/
Direct link: https://downloads.raspberrypi.org/raspbian_lite_latest
This is a good method to make the drive almost impossible to forensic extract previous data, apply this step if you're going to use a previously used microSD card (from a camera, from another raspberry Pi project, etc) so your previous data will be reasonably safe. If you just buyed a new microSD card, this step is not really necessary.