Things that say a lot about people: 

• the way which they treat the waiter/waitress
• how they feel about the weather
• whether they dog ear pages or highlight in books 
• fingernails 
• and hands in general
• their preferred creative outlet
• how much they dread/enjoy talking on the phone
• whether or not they drink coffee
• if they ever forget to eat
• how honest they are with themselves (and others)
• if they correct your grammar
• and whether or not they get nervous before haircuts