USES

Reflexive pronouns are used when:

  the subject and the object of a verb make reference to the same person:

The pilot blamed himself for the accident.("himself" makes reference to the pilot.)
 
The co-pilot did not brake on time and the pilot blamed him for the accident. (This time, a personal pronoun (him) is used because the subject of "blamed" is "the pilot" and the object (him) does not  make reference to the subject "the pilot" but to a different person "the co-pilot.)"

  the subject and the complement of a preposition make reference to the same person:

The man is looking at himself in the mirror.( "himself" makes reference  to the man.)
 
  In some spatial prepositional phrases the reflexive pronoun is optional. You can use an objective personal pronoun instead of the reflexive pronoun:

Paul locked the door behind him.

  you want to emphasize a noun or pronoun:

  When the reflexive pronoun emphasizes the subject of a sentence it can be placed:

• after the subject: Paul himself made the cake.
• at the end of the sentence / clause: Paul made the cake himself.

  Otherwise, it must be placed after the word it emphasizes: Paul spoke to the Queen herself.