Always maintain your main damage mitigator Bone Shield via Marrowrend. Your standard taunt ability is Dark Command, and you have access to a second taunt in the form of Death Grip, which lets you pull and reposition most enemies. Very much the jack-of-all-trades tank, death knights can respond to any threat but lack some of the more specialized focuses that other tanks have. You can have up to three runes recharging at once, so be sure to constantly be spending them.
By consuming and managing their six runes, death knights generate runic power that can be spent on powerful abilities such as Death Strike. An unrelenting force of death that constantly stitches itself back together, the blood death knight is a tank that constantly fluctuates from the verge of death to full health.