I worked out how to automatically run my Wacom tablet setup script in Xubuntu, but in Cinnamon none of those options worked.
Eventually I found the .config/autostart directory and modified an existing .desktop file to start the script. This is what I came up with (I assume the file can be called anything, I just called it xsetwacom.desktop):
[Desktop Entry] Type=Application Name=xsetwacom Exec=/home/<username>/.xsetwacom.sh Terminal=false Icon=terminal Comment=Set up the Wacom tablet rotation Categories=Utility;Application;
(Then I found this post that describes how to do it graphically, which might be easier.)