FOSS Linux published a tutorial about backup and restore your Ubuntu installation with TimeShift.

How to backup and restore Ubuntu with TimeShift

Timeshift is a free-to-use tool that lets you take backup system settings and files. By protecting these important files, you can always restore them if something goes wrong. However, the tool is not there to protect your files, including pictures, music, and documents.

How to backup and restore Ubuntu with TimeShift | FOSS Linux