sympathetic everyman,Winston Smith. From the start, Orwell shows us Winston rebelling against the oppressive system he lives in by writing in a journal. The descriptions of the creamy paper of the old-fashioned journal, the small nook where Winston can write undetected by the view screen, and the pent-up desire Winston has for self-expression cause us to identify with him and participate in his longings. It seems a small thing to be allowed to write in a journal, and the penalties Winston describes for it—death or twenty-five years at a hard labor camp—immediately put us on his side in rebelling. What he asks for seems little enough.

Orwell also develops much of the theme of rebellion through dialogue, particularly the conversations Winston and Julia have about different reasons for hating the Party and, later, Winston's conversations with O'Brien, both at O'Brien's apartment and after Winston's arrest, while he is being tortured. Through these conversations, we learn how Winston understands rebellion and what O'Brien thinks of rebellious people.

Literary techniques is a pretty broad term. I'll give you several examples of different types that can contribute to the development of a theme:

• Characterization: the art of creating a character through the speech and actions of him/her and others
  By developing a character like Julia (the Dark Haired Girl), Orwell shows us the type of character who would rebel against the society in Oceania, pointing out its flaws and illustrating the type of person who actively and consciously chooses to not fit in. 
  
• Symbolism: the use of a physical object to develop a secondary, physical meaning that accompanies the first literal meaning
  
  The glass paperweight, which contains a fragment of coral, symbolizes beauty and the past. The fact that both of these things are rejected by Oceania is significant because Winston chooses to keep and value this object despite the fact that owning it is a factor of rebellion. 
  
• Diction: the word choice an author uses to develop tone
  Orwell's word choice when describing Winston's behavior and perspective is laced with fear, criticism, and confusion. His observations of his society develop a tone that invites the reader to agree with Winston, thereby developing this theme. 
  
• Conflict: the driving forces that develop the plot of a story and pit the protagonist against a variety of other people or things
  One of the main conflicts in this novel is Person vs. Society, which develops the theme of rebellion because Winston, the protagonist, cannot agree with the values and rules of his society.