Way 1 - After buying the Dorian's shield rush to top or bot bush your shield will save you very often. Make sure that once your shield is down you retreat if able because his passive is perfect for tanking damage and doing some damage to the other team. Make sure to minion farm unless your teammate is a character who needs to farm such as Caytlin ,WW ,Teemo but if they aren't then make sure to last hit those minions for some extra money to get your build going. You are going to need to get some temperary gold per lvl items the ones i recommend are Heart of gold, kages lucky pick and philosophers stone (I like to get all 3 but you really need to place in your preferance and play style ). Malphite until you get your chalice of harmony is almost always out of mana but still more then playable. But remember to punish enemy's even with low mana for coming near teammates or minions. Your shard cost a lot but is useful for scaring them from your teammates. Once you have your chalice you can severely punish enemy's.

Pros - Very strong against DPS and Supports, Hard to kill, Can deal as much damage as he can tank, If you use your Ulti right he can act like a nuke dealing huge damage to unaware enemies. Can very easily walk away from fights by using your Q(Seismic Shard)on there fastest champion, Can carry a team after a few kills ( around 4 - 6) with a decent amount of minion kills.

Cons - Is very Mana inefficient at start until you get the chalice of harmony, needs to farm a little and get some kills to be extremely efficient (Not required but is suggested). Is a very expensive build but in the end very worth it.

Fortify - I choose fortify because I believe as a tank you should be giving the team support and it will save your turrets quite a bit. ( If you don't want it use Exhaust instead or Teleport if for some reason you are forced in Mid)

Flash - I used this for team fights for when a enemy champion is running away. This used with your Q(Seismic shard) will insure a definite kill on weak champions. Is also very useful for retreating through walls.

Order to build items - Dorian's Shield, heart of gold, chalice of harmony,boots of speed, mercury treads, wardens mail, Reduin's Omen, Warmog's ,Giant's Belt, Frozen Mallet, Sell your Dorian's Shield for a Guardians Angel

Replacement items - Thornmail and Zohonya's Hourglass. Remove Gaurdians Angel and frozen mallet to replace for these items.

Why i choose these items

Dorian's Shield - It starts you with a good amount of health for your passive and has a perfect amount of health regen to let you stay in the fight longer but also providing a little armor to help you take those strong DPS champions.

Randuin's Omen - Randiun's Omen is an amazing tank item providing health Regen, Armor and a great activating ability allowing you to turn those team fights and those 1v1's.

Warmog's - I choose Warmog's Because they increase your health quite a bit which also increases your Passive granite shield and the health regen will stop you from dieing.

Mercury Treads - This is a very useful item when the other team has alot of CC and Stuns.

Frozen Mallet - It increases your health by 700 which increase your shield alot and its passive ability allows you to slow enemies when you hit them which with flash can get you or your team a kill.

Gaurdian's Angel - Is a great tank item because of the second life you get to run away if your team died or to continue fighting if you are in the middle of a team fight, this and the large amount of magic resist you get makes this a great pick item.

Thornmail - If there happens to be a strong DPS that is being Fed and you can't tank them thats when you go for the Thornmail (If you are getting in trouble because of DPS before you are able finish your Randuin's omen don't worry stop building your Randiuns and start on the Thornmail.

Zhonya's Hourglass - This is for fighting Nukes that can devistate teams but with this you can laugh that damage off once you use its active ability which grants you invincibility for 3 seconds. and also gives a ton of Armor to let you sustain those hits from DPS characters.