How do you chose a good name on social media, email etc

How do you chose a good name or nickname for online life?

How do you come up with a good name on social media?
https://www.reddit.com/r/ArtistLounge/comments/1ckmxyg/how_do_you_come_up_with_a_good_name_on_social/

Help with username registration on X

How to find people on X 

Jak zvolit email, nickname, pro online svět?