The careful narrative of exposition (Miranda spaces out; Ariel
complains) -- 1.2.
A morality-play binary between Ariel and Caliban?
Ariel as "air" Caliban as "earth"
The comic pact enforced by Prospero's power ("art")
The potentially tragic re-enactment of usurpation on the island (2.1)
The defeat of Caliban's rebellion with Stephano and Trinculo. Note that Ariel had to remind Prospero of their approach. (4.1.138)
The masque -- and The Tempest as a kind of masque [video]
The elaborate stage directions (after 3.3.52, 3.3.83, and
5.1.57, for example)
The concept of the "anti-masque" -- Stephano, Trinculo, and Caliban
The masque itself (4.1.60ff):
Its language and structure: the foregrounding of Ceres and
the fear of Venus (4.1.76; compare Prospero's strong defense of virginity before marriage, 4.1.14-22)