Aoba's technique made use of crows but wasn't specifically a technique from the crow contract. There aren't much technique-wise and there are all pretty self-explanatory, So I'll post them and you can just ask any questions you have.
The only actual animal summoning technique of the contract. You summon a large black crow that can be used for various things and deals damage according to its rank by attacking with its beak, claws, and wings.
(Kuchiyose no Jutsu: Kuroi Karasu) - Summoning Technique: Black Crow
Type: Supplementary
Rank: B
Range: Short
Chakra: 20
Damage: N/A
Description: The user will summon a large black crow that stands about as tall as two people with a wingspan of about 5 meters which can be used for various tasks in combat such as generally attacking the opponent or for maneuvering around on the battlefield. The crow itself is only capable of standard physical attacks using its claws, beak and wings.
Note: can only be summoned once
Now for the technique, this first of which is Murder of Crows Confusion. This allows you to summon a massive swarm of crows that fly around a target to hinder their vision and confuse them.
(Kuchiyose no Jutsu: Satsujin Konmei no Karasu) - Summoning Technique: Murder of Crows Confusion
Type: Supplementary
Rank: C
Range: Short-Long
Chakra: 15
Damage: N/A
Description: Summoning a massive swarm of crows, they will fly around the target, causing confusion with their dark forms and quick movement. With the target distracted by the crows, the ninja can strike more easily. Also the mass of crows can obscure any retreating ninja. When no longer needed, the murder of crows will simply puff away in smoke.