The common mistakes

[Jaminos]

There are many good guides out there on tanking mechanics and how to fight bosses, however I see very little about what NOT to do. There are some common mistakes my fellow tanks make that are easy to fix but can cause us no short amount of grief if we break these unsaid rules.

(Please keep all comments as helpful to increase the effectiveness of this quick reference guide)

Wait for the party to catch their breath
The most common mistake I see tanks make is charging into the next fight before the healer and DPS have had a chance to recover their resources. (MP/TP)

Marks your targets
This is a very easy function that we should ALWAYS do. Mark your targets in order of Attack while using the special marks to denote sleeping. ALWAYS TELL YOUR PARTY WHAT YOUR MARKS MEAN! Not everyone has the same opinion on what order the marks mean.

Don't bite off more than you can chew
Another common mistake we make is not thinking before we act. 30+ dungeons jump in difficulty by a huge margin. You can't just charge into every mob you see. You need to spend time to make sure you are not hit with any patrols while fighting and fight only what your group can handle. Usually, three is the magic number. Anything past three and you start over extending yourself. You can only keep so many NPC's aggroed before DPS or the healer picks them up. You might be able to push it to four but I don't recommend it. Most mobs are in groups of three. But not always.

Watch your health
A good healer never let's the tank fall. A better tank makes the healer's job easier. Know when to pop your cooldowns. (Rampart, Bloodbath and so on.) It also is good to know when you are taking more damage than you should. It often means you either were in a strong attack's radius or you have to many NPCs on you.

Think Ahead
Not thinking ahead will always come back to bite you. As mentioned before, your cooldowns are your life. Don't needlessly waist them unless you really need to use it. If you are a Gladiator/Paladin don't waist your Rampart on trash mobs unless you know they hit harder than you can comfortably tank through. If you know a boss is coming up soon. Best to not use them until you are there or at least tell the party to wait while you wait for your cool downs to finish.

On a side note, don't be to conservative either. You should use your cooldowns when they are needed. Don't get to worried though if you think there is a more important mob to use it on. Sometimes the situation forces you to pop them to save your healer and DPS.

Chain XP
Chain XP is great for FATES and soloing. But rushing your party to kill another mob before then chain is over is not a very good idea. Your healer will probably need a moment to rest and regain MP and others might need their cooldowns to finish.

Communication
Communication has been and will always be key to any group. Always let someone know what your marks mean, when you are new to a dungeon, when you need advice and so on. More times than not, your party will help you the best they can. 90% of the time, your fellow party members want to complete the dungeon as much as you do. However, there will always be those who just enjoy being the bad guy to screw things up. Again, communication is key! You don't have to banter with your party. But don't clam up either. They need to know what you are doing as much as you need to know what they are doing.

While not always the case, tanks are usually the ones leading a dungeon. If you don't know what to do, ask. Communication will always be the reason a party fails. Either communicating that you don't know what to do or failing to listen to advice. You are not a tanking god. Just a player with fellow players.

[BlaineCraner]

Also, before you start marking you should discuss with the group what mark means what.
X - attack that
O - Debuff that
Square - Protect/buff/help me!

etc.

[Jaminos]

Tunnel Vision
Tanking Tunnel vision has killed more players than I care to count. Don't get so focused on the boss that you ignore everyone around you. What I do is scroll out as far as I possibly can with the camera so I can see the entire battlefield. You should be split about 60/40. 60% on what's going on around you and 40% on the boss. HOWEVER this does not mean you should ignore the boss by any means. Pay attention to what abilities he is using and the AOE's he is casting. As well as agro always being your top priority.

Face the boss
A good rule of thumb for most fights is to simply face the boss away from the party. This should be an automatic function for you. It is for me at least. You want the boss facing you at all times and not the party because many bosses have frontal cleaves and frontal AOE's. Most bosses will have rear attacks that will hit your party, but all the agro in the world won't help you. It is a forced attack that usually but not always, can't be stopped.

Stun
Not every tank can stun right away. But if you have it, use it often. If you see a slower cast, stun it! Interrupting a slow cast will save from heavy damage on you or your party (Or sometimes both)

AOE attacks
This is a very obvious mechanic of almost every boss. When you see the red AOE pop up, GET OUT OF THERE! Don't just sit there like a deer in the headlights. You will take massive damage or sometimes even a guaranteed death. Some bosses like Titan will confuse this mechanic where being within the AOE is a good thing as long as you are not in the center of it.

Hubris
Don't get cocky! You are not a tanking god! Just because you have awesome armor and weapons does not make you a great tank. Its better to just keep quiet while tanking, unless you need to explain something or say something relevant to the situation at hand. The moment you start acting like you are the most important player on that battlefield, players will drop out. Its ok to have a good time and be friendly. But never overestimate your worth. Everyday a new tank is made. Others will gladly take your spot. Just because higher level tanks are rarer does not mean you are not expendable. I rather fail a dungeon than put up with a tank who makes an ass out of himself.

Know your rotation
Before you start dungeon, always make sure you know what skills do what. If you level up in the middle of a dungeon and get a new skill, spend a moment to read what it does and place it in the appropriate spot in your rotation. You would be surprised how many lower level tanks just spam random abilities, not know what they do.

Taunt
The very most important skill in our arsenal. While I am not as familiar with MAR/WAR tanking, Gladiator/Paladin's all get fairly early on "Flash" our AOE taunt. Use it, use it often. If you see a member of your party have an NPC break off to attack them, grab it quickly. Many tanks fail to use their taunt to its maximum effectiveness. You should be taunting the enemy as much as possible. Just make sure you don't use up your MP because you spammed it TO much.usually your three hit combo done twice is a good time to use Flash if you have it.

Buffs
I always grind my teeth when I see a tank who does not wait for buffs. This is such a simple thing to wait for. Also, please wait for EVERYONE to get their buffs. Don't be a jerk and just rush ahead after you get your buffs. Waiting for the healer to have their MP recover after buffing is also another good policy to have. You will wipe during some boss fights. It happens. Don't charge the boss after your buffs are applied while the healer is still recovering their MP. In the end all you are doing is hurting yourself because it means that's just less MP they can use to heal you during the boss fight.

Gear
I never watch videos of a dungeon before I go into it. I love the surprise and figuring out each boss. HOWEVER, I do look up the recommended gear requirements for every dungeon. After Manor, dungeons in the level 30± range jump up drastically in difficulty. Gear becomes an important corner stone to any good tank. Make sure your gear is always at least within four to five levels of the dungeon. Anything less and the NPC's will take you down before you knew what hit ya.

Also, pay attention to what you are rolling on during boss loot. Just because you can use it, does not mean its for you. Sometimes other DOW gear drops and while you can wear it, leave it for other DOW classes unless it is such an important upgrade that you HAVE to roll on it. But usually this means you are under geared as mentioned above.

[Jaminos]

Also, before you start marking you should discuss with the group what mark means what.
X - attack that
O - Debuff that
Square - Protect/buff/help me!

etc.

I wrote something to that degree but I will fix it so it is clearer.

[Animation]

Very nice.

As for this part - "Don't bite off more than you can chew"
That is dead on, I see a lot of tanks just dive in and pull aggro for like 10 mobs, this burns the healers mana way to quick and if anyone else takes aggro then it makes the healers job x10 harder as the tank is taking a lot of damage rapidly.

[Jaminos]

Very nice.

As for this part - "Don't bite off more than you can chew"
That is dead on, I see a lot of tanks just dive in and pull aggro for like 10 mobs, this burns the healers mana way to quick and if anyone else takes aggro then it makes the healers job x10 harder as the tank is taking a lot of damage rapidly.

Thanks! I appreciate it! Again, if anyone has any suggestions, let me know and I will add them to the list.

[HEC]

Buffs
I always grind my teeth when I see a tank who does not wait for buffs. This is such a simple thing to wait for. Also, please wait for EVERYONE to get their buffs. Don't be a jerk and just rush ahead after you get your buffs. Waiting for the healer to have their MP recover after buffing is also another good policy to have. You will wipe during some boss fights. It happens. Don't charge the boss after your buffs are applied while the healer is still recovering their MP. In the end all you are doing is hurting yourself because it means that's just less MP they can use to heal you during the boss fight.

^^^^^ THIS!

It makes my blod to boil when I see tank (or any othe class / party member) to ignore this rule ...

What I do now is to buff tank as last and then say "Ready" or just "R" in the party chat. This will also keep my target / selection on tank to be able to heal right away.

[MisaCeliousa]

Forget Chain Kills
While getting chain xp is nice, don't use this in groups made with duty finder, people usually can't keep up and it easily leads to a wipe

[Jaminos]

Forget Chain Kills
While getting chain xp is nice, don't use this in groups made with duty finder, people usually can't keep up and it easily leads to a wipe

Added!

Thanks!

[HEC]

I think what you should have on TOP of the list is:

Communication!

Don't need to discuss strategies for minutes, simple "Ready?" / "ready" or "go" will do a lot in most of the situations. Even to say "Hi all" at the start of the dungeon or not to be ashamed to say "It's my first time as [put your class here] as I'm leveling the secondary class so please be patient with me" will do no harm. I tend to tell party "Please wait, running low on MP" although I know they can (and should) watch the bars in the party list and so on. As long as you're nice and polite and not trying to be despotic or too controlling even when pointing some "misshaps" of others you'd hardly ever get really negative response to that and if you do at least you know who you're dealing with ...