Spec for 100 Resilience and Discipline, then get as much Recovery as possible. Use your grenade first, then cast either Howl of the Storm or Rally Barricade to spawn more crystals. Shatter your crystals to gain HP, overshields, and ability energy. With max overshields and the DR from Whisper of Chains, you should win virtually every Primary gunfight. If you're not using Cerberus, swap the Kinetic mods to match your Primary of choice.
These build settings contain: