Do not write frequently to the SD Card. Consider writing data that does not have to be persistent to a ram disk.

The ram disks ls /dev/ram* seem to be leftover from early Debian versions and are not used. They could be used however using mount -t tmpfs -o size=256M tmpfs /mnt/tmpfs is simpler and more advanced.

More easy is /run/user. This is also ram disk as cat /etc/mtab | grep tmpfs shows and has even the access right set for users.