Giratina Origin Forme Movesets

Calm Mind-Modest Nature-Griseous Orb
Calm Mind
Substitute
Aura Sphere/Shadow Ball/Dragon Pulse
Dragon Pulse/Shadow Ball/Aura Sphere

For this set first use Substitute then Calm Mind behind it. For the three attacks it's best not to go with double STAB because they are both resisted by Steel, which Aura Sphere nicely covers.

Physical Attacker-Adamant Nature-Griseous Orb
Shadow Claw
Dragon Claw
Earthquake
Draco Meteor/Wisp-o-Willows/Stone Edge

This Moveset lets you hit the generally weaker side of Ubers. Shadow and Dragon Claw have almost perfect type coverage. Draco Meteor is a strong attack but Wisp-o-Willows lets you cripple threats such as Groudon. Stone Edge lets you destroy Ho-Oh but it's not a common Uber.

Special Attacker-Modest Nature-Griseous Orb
Draco Meteor/Dragon Pulse
Shadow Ball
Aura Sphere
Thunder

With the Griseous Orb you can freely switch between moves, giving you a slight advantage over Choice attackers. Draco Meteor gives you a very strong attack to work with but if you don't like the Special Attack drop then go with Dragon Pulse. Shadow Ball is a STAB move and lets you get super affective hits on the many Psychic Ubers. Aura Sphere lets you get perfect type coverage and Thunder hits Kyoger super effectively.