from a Raspian Buster (Debian 10)
After burning a new SD card one finds quite a huge, already installed software package. To get more space on the SD card one can remove all unloved and unused packages. For example these:
$ sudo apt update $ sudo apt remove --purge claws-mail minecraft libreoffice-core wolfram-engine $ sudo apt autoremove
That will save around 2 GB of space.