Couldn't resist reposting this from the bottom of another thread.
How to play a cleric in the Shroud raid.
1) Be the first to enter. Zone in to the instance on Elite.
2) Cast resists if people ask for them. You want them to have a false sense of security.
3) Don't cast Freedom of Movement. If someone else casts it, dispel it. This will become important in part 5.
4) Some people aren't team players, and use Vicious weapons or Barbarian frenze. Don't heal these people. They need to learn respect for your spellpoints, which are needed for more important things than healing, such as dispelling FoMs.
5) Upon reaching the third portal, turn around and activate a clicky of everyone's favorite party buff, Grease. Try to aim it and time it so that people land on the spikes, they provide powerful buffs on elite.
6) Work on achieving an extremely high Wisdom and Spell Penetration. Cast Symbol of Persuasion near portals often, (the mobs are not immune to it), as you don't want the party getting overrun. Portal Keepers are especially good to charm in this way, their fire spells are devastating to the portals and the orthons.
7) Summon an Efreeti or Hellhound. Their fire attacks are particularly useful in here.
8) Open the chest at the end of part 1. If there is a Shard of Power in it, leave it in the chest and recall out. Otherwise, step into part 2, run straight to the center of the maze, aggro the four bosses, and run to the south-central area, die, and release out.