You may have read some threads on r/linuxmint and on the Linux Mint forums that you can disable mouse acceleration with the
xset command, but I couldn’t get it to work for Mint 19 Cinnamon. As I later found out, this is likely due to Mint 19 Cinnamon using libinput as the default input device driver.
In short, what I had to do to disable acceleration was to create the following file:
Section "InputClass" Identifier "My Mouse" Driver "libinput" MatchIsPointer "yes" Option "AccelProfile" "flat" EndSection
into it. Then restart my PC.
I thought I’d post this to help new users to Linux like myself.
Credit to the Arch Linux wiki for the straightforward guide: https://wiki.archlinux.org/index.php/Mouse_acceleration#with_libinput
More discussion about the above method here: https://www.reddit.com/r/linux_gaming/comments/535ng5/how_to_disable_mouse_acceleration_with_libinput/