On Ubuntu 12.04 there is an interesting application called Systemback. Systemback is a GTK application which can be used to backup our system in single click. Like in Windows OS, Systemback allows us to create system restore points. So we can go back to the previous system state if anything happened to our Xubuntu.
To open Systemback, simply go to Applications menu | System | Systemback. Or you can also execute it via command line with command
sudo systemback
On the main window, simply press Create a new restore point to create new one. The available restore points will be displayed on the main menu so we can easily go back to the selected restore point.