You get a commendation by leveling up the rep for one of the factions/crucible/vanguard, but only once you hit rank 3. You can send your rep from bounties and patrol missions to a faction by wearing one of their class items (which you can buy at anytime with glimmer). Once you have done all of your bounties there is really only one way to get rep...and that's patrol missions. Or if you want crucible rep then you have to play crucible. Edit: Higher level gear CAN drop from the strikes but will be rare...if you have enough marks you can buy light 33 gear from the vanguard. You don't need a commendation for the boots or the gauntlets.