Ramp
Ramp is about accelerating land deployment and/or mana access. Azorius really has no options here (in exactly two colors).Card draw
White likes life gain, and blue excels at card draw. It's not surprising that Azorius has many options that give you both, be they creatures (Cloudblazer, Elite Guardmage) or instants (Sphinx's Revelation).
Targeted removal
White likes permanents that exile creatures while they remain on the battlefield; blue likes countering spells. Azorius has options in both. Absorb and Dovin's Veto are nice counterspells; Lawmage's Binding and Deputy of Detention are useful exile permanents.
Board wipe
White likes wiping the board; blue likes returning creatures. Time Wipe does a little of both, and Supreme Verdict is a nice way to get creatures off the board.
Combos
Hindering Light is both a counterspell and a card draw aid. Azorius Charm can help you draw a card or remove an attacking/blocking creature.
Conclusion
The 11 cards shown above are easy 'includes' in any Azorius Commander deck.