As reported by droidlife, YouTube TV is testing custom channel guides.
This will allow you to sort your channel lineup in a custom order instead of the default which is currently alphabetical. This is most similar to the “Favorites” feature on most other providers where it places your favorite channels at the beginning of the guide.
One additional feature is the ability to hide channels, so they never show up in your channel guide.
To access the feature on Android, go to Settings —> Live Guide —> Custom. Just drag or remove channels to create your own custom channel lineup.