For trash packs, at 54 finding this to work pretty well:
(Plunge+Salted Earth where I'm putting them) -> Unleash (Dark Dance+Blood Price) -> Unleash (Dark Arts+Dark Passenger)

Then it depends on size of pack. Keep spamming Unleash until Blood Price drops, on big packs keep spamming or start single target rotation on 3 or less. Generally turn off Dark side about 50% of way through last mob to start ticking up between camps.