Observe 4 things: Physicality-Fitness, hair,age, and grooming habits

Observe 4 things:

1. 
   Physicality-Fitness, hair ,age, and grooming habits.
   
2. 
   Attire - Dress, shoes/footwear
   
3. 
   Verbal communications - tone of talking, change in pitch and vocabulary.
   
4. 
   Non verbal communications - Gestures,body language etc.