Show your characters’ expressions. I tend to get Eileen to grimace a lot (!) (though to be fair she does have cause) and am aware I need to vary her expressions. Also show your characters trying to hide what they really feel - after all we do it so why shouldn’t your creations? What happens when a character fails to hide how they feel or shows their emotions to the wrong person? What catastrophes could be unleashed?
How do your characters conduct business? Have you got the Del Boy type? What are the rules? How are these circumvented (someone’s bound to try aren’t they?) and what are the punishments when folk are caught out? Is there a fantasy Inland Revenue?! (The mind boggles a bit here. Can you imagine? Instead of the £100 penalty fine per day if you’re late filing your return, the Fantasy Revenue could turn you into a toad, smash you into a pulp, cast imaginative curses if you put the wrong stamp on the envelope and so on!).
Let your characters have their own lives. Whilst you invent them and control them, that control should not be to the extent they lose any sense of personality. You don’t want puppets. Leave them to Thunderbirds ….
Flora and Fauna
Think about flora and fauna. Even sci-fi/fantasy worlds have their ecosystems, predators and prey and so on. And especially in a fantasy world have a look at how magic affects them. For example does it make them more aggressive? Do they need magic to live at all? Could they survive on earth? Would earth be beneficial or harmful with no magic about?
Does your world have specialists? Eileen is a specialist in her field, as was Rose. Does that lead to envy in others or are the specialists left to it as they face more risks than most?
What threatens your world? Has it done anything to deserve it?
How do your characters’ lives change? Long term characters especially should have plenty of ups and downs. The ups shouldn’t be saccharine sweet. For the downs, there should be some hope they can get out of them. (If you want constant despair, watch your average party political broadcast!).
Do your characters develop relationships? Think about all kinds of relationships as well as the obvious romantic/sexual ones. Is there part of their personality that makes forming relationships difficult? Do they find a particular type of character difficult and if so have you shown why?
How do your characters’ relationships change? Relationships don’t stay static. Relationships should be a major part of your plot, should complicate things and give your characters both hope and despair. Think about how your character demonstrates anger, frustration etc.