Sniping from afar

If you like sniping with the sniper rifle or pistol, the rockslide megabattle provides quite a shooting gallery, especially if take care to maximize the enemy count. For example there are great sniping possibilities in the Far area defence and Lifeboat rush, where you have a horde of enemy coming at you across a plain. The Island plateau defence is another excellent sniping situation. But aside from any specific plans such as those, you can always just move around the periphery of the rockslide area looking for opportune targets - possibly trying to remain undetected. See here for advice on getting a sniper rifle topped up, ready to take into battle.

When Jackals do good

With distant sniping, the enemy often congregate in numbers as they face up to you, and sometimes comically hit each other with friendly fire. That's well worth looking out for, and you might even try to help engineer it. Sooner or later you'll see an Elite get hit from behind by a Jackal's overcharge shot. If you've got a pistol handy, finish him off with a few rounds.

Long range grenading

Another pleasure here is in lobbing grenades into the massed enemy ranks that tend to form in front of you. In particular, once you've taken down some Grunts and Elites the floor should be littered with plasma grenades, making things ready for setting off a chain reaction blast for maximum carnage.

Recoiling Elite

When sniping an Elite, try hitting him somewhere other than the head to see how he recoils appropriately. It's another fine example of Bungie's craft.