Currently experimenting. The idea is to isolate any services where I'm not confident yet in their security/quality. The hope is that if there is an exploit in a given service that an attacker won't be able break out of the docker container and cause damage to my systems.
An example of a service I would isolate in a docker container would be a minecraft browser map application I use. I don't know who wrote it, I don't know who's vetting it, I don't know the source code. I would feel a lot better putting this in a container before I expose it to the internet.
I believe I will follow this process for anything that's not properly maintained (not in an trusted apt-repo or some other sort of confidence)
I use box as an broker between my phone's data storage and my home networks backup storage. Box allowed me to automated backup of photos and videos to their cloud storage and in turn, schedule syncs of this data from Box to local network storage. This is a decent solution for me as it essentially offers on-premises backup in case I lose my phone and it also offers off-site back up inherently in case of local data loss, fire, etc.
I use openCV to serve as "motion capture" logic for my home security cameras. Which means that instead of capturing in a dumb way based on motion, it captures video when it recognizes human faces or bodies. This saves a lot of disk, but at the expense of CPU.