Every baby has its own unique identity, from what they find comforting to what they find scary or agitating and it may be very different to their siblings or other babies you know. 

Watching the signals they give you to share their feelings will help you understand what interactions makes your baby feel most comfortable. 

Go back to basics and try turning off the tv or electronic mobiles and using your voice to sing to them instead. Play simple, gentle games like peek-a-boo or recite nursery rhymes.

When you are looking at your baby think about how you would describe your child's personality to others.

Think about what they like and dislike. Do they like noise or silence, or a particular kind of music? Try out different types of music to see if they find any of them irritating or soothing.

Watch to see if there is a particular toy that they are attached to.

What do they do or how do they interact with you when you are on the phone, or busy around the house.

Would you say that they behave differently from your other children or friends' children? In what way?

Do they like to be bathed or changed into clothes?

Do they like to eat? How would you describe the speed of their eating and do they enjoy the attention you pay them during?

Make sure you keep a record of everything you are observing especially as it will enable you to notice any changes.