Just posted this in another thread:
Please note: If you’re planing on using Timeshift for making snapshots later on make sure to set up your subvolumes correctly.
Timeshift’s BTRFS snapshots are supported only on BTRFS systems having an Ubuntu-type subvolume layout (with @ and @home subvolumes).
For a really quick way to set up btrfs and timeshift maybe check the following post which describes how to adapt the BTRFSonLUKS wiki article to not use encryption.