I hide things and places in mine that people in my little subculture would notice. But not that members of the public would spot. I doubt that counts as an Easter egg... maybe?
All the times specially to estabilish their interconnection. But they are not that easy to find only to those that read my other works. Mariposa for example has at least 3 in the upcoming pages.
Created a fictional comic con just for the Easter eggs,will add a few in prologue.
Mine has an extended universe connecting it all, so there's a bunch of easter eggs everywhere hinting at lore or other stories.
Does hints that connects to the next installment of the story considered Easter eggs?