How does fitzgerald use sarasm and irony to convey his point of view about society during gatsbys

[What a fabulous question!  I really enjoyed thinking about this, . . . and it took me a long while to formulate my answer as a result!  I originally thought Tom would be the main culprit but then I couldn't think of a single example.  Honestly, I hope some other teacher figures out some further examples to add to the rich content here.  This being said, my answer follows.]