There is probably a post on this already, but I really didn't want to look. I am pretty sure this is a glitch, but if you are in a dungeon, and you have 5 shards before a boss, and the group you are in is kinda slow, if you spam demonic empowerment, your shards do not decay. This makes the starter SO much easier.
My starter with 5 shards is precast empower, doom, doomguard, grim of service, demonbolt, HOG, empower, demonbolt, demonbolt, dreadstalkers, artifact power, then into normal rotation.