Race: Redguard
Optimal alternative races: Imperial, Orc, Nord, Breton, Dunmer

Attributes:
0 Magicka | 12 Health | 50 Stamina

Key numbers to hit:
20,000+ Stamina, 27,500+ Health

My numbers (with food buff):
21,221 Stamina, 27,538 Health

Armour: 27,533
Buffed Armour: 32,653
Spell Resistance:25,033
Buffed Spell Resistance: 31,113

Key numbers to hit (with buffs):
Note: ~32,500 is hardcap for armour/spell resistance mitigation
30,000+ Armour & Spell Resistance (ie. ~46%+ mitigation)

Mundus: Lady (Increased Armour)
Dragonknight passive ability gives 2,500 spell resistance so in order to balance my mitigations I opted to use the Lady mundus.

Infection: Werewolf
The 15% combat stamina regeneration is too good to pass up.

Note: All armour pieces are heavy
Head – HistBark – Reinforced – Health Enchant
Shoulders – HistBark - Reinforced– Health Enchant
Chest – HistBark - Reinforced– Health Enchant
Gloves – Footman - Divines– Health Enchant
Belt – Histbark – Reinforced (Could use Divines)– Health Enchant
Legs – Histbark - Reinforced– Health Enchant
Shoes – Footman - Exploration– Health Enchant

Necklace – Footman – Healthy – Reduce block cost
Ring 1 – Footman - Robust– Reduce block cost
Ring 2 – Footman - Robust– Reduce block cost

Sword – Death's Wind – Defending – Hardening
Shield – Death's Wind - Reinforced– Health Enchant

Restoration Staff – Histbark – Defending – Magicka Drain

Alternative Gear:
As I lack the Bloodspawn Undaunted shoulders I cannot use this set. However, if I did have them, the 2 piece Death's Wind would become Hist Bark and the Head and Shoulders of Hist Bark would become Bloodspawn.

Reasoning:
Footman's 12% block mitigation and health/armour/spell resistance buffs is the key to any tanking set so it is a must.

Histbark allows you to dodge projectiles and single target attacks while blocking. This is perfect because PvP has moved into a more single target orientated combat system. Further, it saves a great deal of stamina as you dont need to block attacks that you dodge.

Death's Wind is being used for the 2 piece armour buff so that it is possible to hit hard cap. Bloodspawn would allow you to hit hardcaps in both armour and spell resistance and allow for 2 light/medium armour to be used for cost reductions.

Reflective Plate – Reflective Scales is a must as a tank I believe. Range damage is extremely common in Cyrodiil. Reflective Plates allows you to save on some stamina by not having to block 4 of those range attacks. Further, bow projectiles usually carry with them healing debuffs which have to the purged so reflecting those is ideal & also, with the change to the Meteor ultimate, it is now a very common sight in Cyrodiil and as such, timing your reflect to reflect those meteors provides damage, CC and group protection in one skill. I chose the Plate morph because the minor spell resistance buff lasts for 20 secs and means that your always bordering that hard cap mitigation.

Absorb Magic – Passive block mitigation (couples well with the Footman set) and passive block cost reduction is perfect for a tank, so again it is a must. I chose the Absorb Magic morph as opposed to Defensive Stance because the heal is very powerful for such a cheap ability. 15% of max health heal coupled with all of the passives and actives we have actually boosts this heal to 25%+ of max health heal.

Hardened Armour – Provides major armour & spell resistance buffs so its a must have. Again, I chose this morph because you have no dps, so the aoe dot isn't necessary. It provides a 10% max health damage shield as well which is nice to have to soak up some of the damage.

Igneous Shield - Large damage shield that scales off health (about 8,000 shield). The real purpose of having this skill is to provide stamina due to the Helping Hands passive in the Earthen Heart Tree. It also activates Mountain's Blessing which grants 3 ultimate and also boosts the weapon damage of allies within 30m by 5%. And lastly, it provides major mending, boosting healing you do by 30%. The major mending allows your Absorb Magic to hit that 25%+ max health heal.

Choking Talons – Best crowd control ability in the game. As you have virtually no dps, I have opted to use the Choking Talons morph to provide damage debuffs to the enemy in turn helping myself survive easier and more important my group in case they get targeted. The minor miam 15% damage debuff lasts for 7 seconds regardless if they roll out of the talons or not.

U. Ferocious Leap – Cheap ultimate, provides a 85% max health damage shield (in Cyrodiil), gap closer and a aoe CC. Enough said.

Cinder Storm – Most people have abandoned Cinder Storm because it has lost its miss chance. I however like to use this skill still. It can now be placed up to 24m away which allows for you to control the enemy from a distance without even trying. The snare persisting even after they have left the area means you can keep melee users at bay.

Spell Symmetry – Your lack of a magicka pool and so many magicka abilities on your bar makes this vital. However, knowing when to use it is key.

[Flexible Spot]
I have no definitive skill for this spot on my bar. I have been experimenting with Fozzile but I find the lack of range a issue. I am working on getting Volcanic Rune, as this would provide aoe CC and also have great range.

Retreating Maneuvers – Running keep to keep takes a long time. Always have this to provide the speed buff. Also its nice to use when your group is about to go into a keep or when you are trying to escape or re-position.

[Healing Flexibility]
Usually this would be the spot of Green's Dragon Blood. However, the cost coupled with your low magicka pool makes this a hard choice. Instead of GDB, I would suggest to use Vigor if you have it unlocked. The heal is fairly large due to our big stamina pool. Also it provides group healing. Alternatively, I am beginning to experiment with Healing Ward. The combination of Spell Symmetry and Healing Ward looks promising. In the mean time, I would just keep GDB here.

[Ultimate Flexibility]
U. Again, we have some flexibility. Look at what your group is lacking and fill in the gap. I like to cycle between Shifting Standard for the aoe healing debuff, Barrier for the group damage shield and Ice Comet for the aoe CC and snare.

I have currently ~90 Champion Points so this is how I have allocated them.
Warrior:
20 points in Block Expertise in the Steed – Reduces the cost of blocking which is always helpful as a tank.
5 points in Elemental Defender in the Lady – Reduces the damage of Flame, Frost and Shock. Always good to reduce incoming damage.
5 points in Hardy in the Lady – Reduces the damage of Poison, Disease and Magic. Again, good to reduce incoming damage.

Mage:
30 points in Blessed in the Apprentice– Increases healing you initiate. Increases the healing of Absorb Magic & GDB (or Vigor or Healing Ward)

Thief:
10 points in Magician in the Tower– Reduces the cost of Magicka spells. Additional help to manage magicka.
20 points in Mooncalf in the Lover– Increases stamina regeneration. Always helpful to have more stamina.

This build is directly applicable to PvE. The only change is to swap Reflective Plate with a taunt.

I wont go too in-depth as I think the best way to learn how to tank is to learn from experience and learn from your mistakes. That's how I have learnt to play a tank.

Basically this build allows you to block for a very long time and mitigate a ridiculous amount of damage. You will be the shield of your group and they will thank you for it.

Always stay in front of your group so that you can protect them and also aid the group my communicating what you see (because you will have the most visibility) and if/when you need resources (ie. So you can get spear shard from your Templars to maintain your stamina)

Some key notes about how and when to use the skills are:

Reflective Plate – like I mentioned above, use it wisely as Magicka is limited. The only time I use this ability is when I know a meteor is about to hit me so I can reflect it or when I feel like I am getting bombarded by arrows from archers.

Absorb Magic – Use this whenever you drop below 85% health or if you are about to get hit with a meteor and have no Magicka to use Reflective Plate.

Hardened Armour – You need to have this buff active 100% of the time. No questions or exceptions.

Igenous Shield – Use sparingly as well. Best time to use this is when you are low on stamina and/or low on health so you can get a boosted Absorb Magic heal.

Choking Talons – Use this if the enemy is in/around you because this is when you wont be getting targeted by single target so Reflective Plates and Igneous isn't as necessary.

Cinder Storm – Clog up choke points (ie. Breaches) with this.

Spell Symmetry – This is the most important skill to learn how to use properly. If you Spell Sym at the wrong time, it will kill you. You must learn how to use this from trial and error. For the best results on Magicka regeneration, combo Spell Sym with a Resto heavy attack. It will give you nearly a full bar of Magicka again.