What kind of email or social media naming style is best for pseudo-anonymity?

What's better for pseudo-anonymity, usernames that are totally random char/number combo that's unique or common popular name that's used by many people on different forums? Do you tend to use the same username on multiple forums or have issues with being mistaken for someone else on a different forum?

I know email/social media isn't secure or private and the providers can see what I send/read, but would like to prevent randos from stalking.

Background: I moved to Japan, I have …

anonymity char email forums kind media name people popular privacy random social social media username usernames