Enemies as shields

When you've got an enemy close - and I'm thinking especially of Elites here, though combat Flood can be another good case - he can potentially act as a shield between yourself and other enemies with a line of fire. With intelligent movement you can make it so. Not only does this reduce the amount of heat coming your way, you may even get the benefit of friendly fire! I've seen Elites cut down by grunty fire that way, ha ha.

The closer your living shield is, the better protection he'll afford. Sometimes I'll deliberately move in close to an Elite with this in mind - probably while drilling him with bullets or plasma. If you see him shaping up to give you a whack, you can backstep to avoid it, continuing to get the benefit of his protection.

This tactic of using an enemy as a shield is probably at its most valuable when you're trying to take on two Elites at once - either because you've temporarily lost your sanity or you've got caught out, or because you just like living dangerously. I find it especially useful in megabattle situations where you have multiple enemies coming after you.