Techniques to reduce the size of the attack surface of a system

Document-1: 300 words, APA, NoPlagarism

Describe techniques applied or approaches taken that can reduce the size of the attack surface of a system.(300 words)

Document-2: 200 words, APA, NoPlagarism

Describe what it means to think like an attacker.

If supporting evidence from outside resources is used proper citation is required. 

Your answer should largely consist of your own thoughts and ideas but may be supported by citations and references.