Some things I notice.

• eyes and eyelashes, wrists
• the way someone whispers in your ear
• piano hands and fingers
• people who enjoy the magical world of Harry Potter
• similarities between a situation and a Bob Dylan song
• earlobes
• the organization of a music collection
• handwriting
• recurring themes and colors
• unique political/religious views on facebook
• imperfect noses (beautiful noses)
• color coordination
• patterns