For gold games:
http://kalence.drupa...13W53314!DFG55O
Cloak -> Freeze -> Reegar, it 2-shots Brutes and Banshees most of the time
For platinum games (when your teammates aren't terrible):
http://kalence.drupa...13N52324!ED9C3O
Generally keep the Recon Mine at the same spot, typically a choke point and only detonate/reposition if spawns are on other side of the map.
Proxy Mine + Acolyte + Cryo = tech explosions, stagger, and an additional dmg debuff.
Shield Boost when needed for yourself and allies, takes precedence over proxy mine.
Volus cloak just makes the character feel overpowered, abuse it.
For platinum games (when you have to carry):
http://kalence.drupa...!24Y56324!E8G.G
I basically just act as a tank for everything so my teammates dont get overwhelmed by the difficulty. Stick to areas that are somewhat protected though (i,e, Landing zone of Giant). Keep the Geth Turret out of line of fire but in range to recharge your shields, you're not using it for its damage. Hex Shield to mitigate incoming damage, and since it blocks friendly attacks be mindful of its position as it relates to your teammates and the enemies. Don't use Siege Pulse offensively, keep all four up for the damage protection. Acolyte from afar to strip barriers/shields, heavy melee when they reach you (better to wait for them than try and make that slow walk towards them). I've found the Scorpion pistol and Reegar shotgun work well too.