I'm looking for a template with no more than a +1 LA that grants Damage Reduction. If possible it would be best if it applied to Humanoids but I can also make Monstrous Humanoid or Giant work. I am aware of Mineral Warrior, but it doesn't serve my needs.
Unseelie Fey, a +0 LA template grants DR based on your HD, but also extra damage against you from enemies using iron weaponry.
There are a bunch of templates that are "LA —" (i.e. Not For Players) that grant DR, amongst other things.
Half-Fey is +1 LA and gives DR 5/cold iron. It can be applied to any living corporeal creature.
The Half Shadow and Half Dragon have damage reduction too.