Sherlock strikes again. I think that by this point he makes his deductions by second-nature, but I bet when he was younger he did it just to impress people. He's cheeky like that.
Meeting the Regular
Chestnut curls, alabaster skin, clear blue eyes, and an imposingly tall, beanpole frame greeted the considerably smaller John, who smiled at the scarfed customer.
"Can I help you?"
"You write a lot," said the dark-haired stranger with a bored glance over John's frame. "You really shouldn't have a part time job when you stay up late handwriting essays."
John blinked, wondering if he knew this man. "Erm...can I entice you with our new Colombian blend?"
A flicker of annoyance crossed the customer's eyes. "Just Earl Grey, thank you. And one of the white chocolate biscuits, if you please."
Prompt was #67: chestnut