Some helpful ground rules that I explain to every group I go down there with. These rules are also applicable to nearly any mission or quest in the game. Apply them liberally to most situations.
1. EVERY player must bring a RESURRECTION SPELL of some sort. If you don't have a monk as primary or secondary, then bring your signet.
2. If all you have for your res spell is a SIGNET, then do NOT use it unless ALL monks and monk secondaries are dead. Exhaust all other options for resurrection before using a signet.
3. One person (commonly the party leader, but not always) will be the DESIGNATED LEADER. He is responsible for party direction, calling targets, and drawing on the compass. You will follow this man's directions under all circumstances. He's done this sort of thing before.
4. When a target is called, everyone will ATTACK THE SAME TARGET. Common priority is Monks > Mesmers > Elementalists > Rangers > Warriors. Shadow Beasts rank somewhere in the middle. No sense trying to beat on a Shadow Warrior when there's a Shadow Monk healing from the back lines.
5. When the party leader says "RUN," you will RUN. You will run such that you do not aggro new groups. You will be smart about this.
6. Sometimes you will be asked to TAKE A DIVE to save others, especially when you're running away. Do it, unless you can give a valid reason why not.
7. Do NOT TALK to ANY NPC's without consulting with the group. Do not accept quests from anyone without consulting with the group. You will not talk to Rastigan until you've killed all the Shadow Army and retaken the tower. No questions allowed.
8. You will NOT AGGRO a mob until the entire group is ready. You will wait for casters to regen their mana. You will let health be restored. Patience, young Padawan. The Force is not with you yet.
9. Do not LEAVE the party for NO REASON. If you have to go do something, either in the GW Universe or in Real Life, let us know. Please be courteous.
10. "OMG ONE PERSON LEFT NOW THERE'S ONLY SEVEN GUYS" is NOT a valid reason to leave the group. Last night I had a 5 person group (all three warriors deserted after the first quest) complete the Wailing Lord quest. Yes, two monks, two elementalists, and one ranger managed to complete that quest. It was hard. We were victorious.
11. EVERYONE should pay to enter the Fissure. I've recently been magnanimous, and been paying for groups. I've since learned that people have an entirely different play perspective if they have money riding on the line; even if its only 125 gold. People that are along for a free ride are usually more reckless, and more apt to quit.
12. Use your COMMON SENSE. Most people seem to leave this behind at the Statue of Balthazar in the ToA. If a situation arises that we haven't covered how to deal with, then try and be smart about it.
Now if only people actually listened and IMPLEMENTED these things, we'd all be happy.