A tip for those that use the YouTube mobile app and care about limiting online data collection of personal information (aka digital fingerprint).
If you have signed in to the app to interact, upload or other feature but want to sign out after, Google has hidden the sign out option on at least newer versions of the app on at least Android. Below is how to find it again.
If you want to stay signed in or regardless you can still clear history and pause history (watch and search) under settings. It says this will prevent them from recommending content (and likely ads) they think you will like.
There is still collection of data online from what you watch for use by Google and content providers for analytics and other purposes but at least you are limiting some of what is tied to your personal accounts directly.
Here’s how to find the sign out option again:
From the phone’s settings (not app settings) go to Apps and select or search for Youtube, then storage.
Select “Clear Data” button.
Open Youtube app. You should still be logged in.
Select Account icon. On Account page select “Switch Account”.
“Sign out” should be now visible on the popup window.
More information on other privacy tips and some of their limitations: