Usernames

Anagram a sentance of my real name.
Then changed the anagram sentence into an initialism.

Random words with a "last letter first letter" rule, eventually stuck with one, then later got refined down to something less cringe-inducing.
As for characters I'd go with a stupid rendition of whatever role they had.

I usually go with "Complete Idiot" or some variant.
Nobody can criticize me, ever. What are you going to do? Call me an idiot?

I assort random letters into sub-words, and combine them into something that works.
I only use one username, but I use this for Character naming conventions.

Holy shit, I hate you. I always have to have a name that is pronouncable by humans, but that is just me.

Similarly, I use Toidinamai, it's great when don't realise what it means.

I've never had a user name of my own. I always steal it from someone random and maybe add some little variation to it.

...

My runescape account that is almost two decades old is 'Dude' with a random string of numbers

A random word is the best username you could use like