(Of course, if it’s done successfully, you will fake the organic nature of a character trait.)
Then, after being traumatised through his amputation and ungodly provenance, he has to build his own new lightsaber out of the cheque he received from his very bad Jedi healthcare plan. (Not really.)
Impatience is a major failing of the Skywalkers that feeds into the plot (in a good way). The incorporation of similarly subtle characteristics is better than constant sighing or ARE WE THERE YET type stuff.
You can milk a tic or quirk for humour too. In much literature and comedy, writers use the “rule-of-three” and the idea of call-backs, where they reference a previously made point.
Or there can be a set-up and a pay-off related to a quirk. And all-the-better if the quirk itself can seem like not-a-quirk at all.
A character explains his motivation for not trusting his psychiatrist. He says to the psychiatrist:
“Doctors have to do very well in school. They have to be very intelligent. Psychopaths are often highly intelligent too. A lot of doctors – particularly mind specialists like yourself – must be psychopaths.”
His psychiatrist talks about his qualifications and principles to try to get the character to open up. Finally, the patient is convinced to reveal his secrets.
But it turns out that this shrink IS a villain in the story after all.
Later on, while this same psychiatric patient is held at gunpoint by the psychiatrist-villain and his goons, he meets an astrophysicist, who has also been taken hostage by the psychiatrist.
“Don’t take this the wrong way,” the patient says as they’re introduced to each other and thrown into a cell, “but I don’t really trust astrophysicists.”The psychiatrist roars at him to shut up.
Just show her being a wallflower, or checking the last dialed number on someone’s phone.