My name is Kevin, and this is my guide/build to use Shen.
It's my first build, so I thought I'd give it a try!
All suggestions, trolls, comments, and votes are appreciated!

You can add me in-game: zyzzthetics

What are "the good, the bad, and the ugly" things about Shen?

The good:
- able to stay in a lane for a long period of time due to his Q ability
- can "turn the tables into your favor" by taunting the entire enemy team in teamfights, allowing squishies to attack freely (and/or run)
- uses an energy pool instead of mana
- can save many allies using his ultimate
- can use his taunt ability to go through small ledges (some walls also)
- great early game burst damage even without damage/AP items
- extremely mobile with teleport
- a ninja tank!
- has a global ultimate, allowing him to be even more mobile
- is a "flippin' ninja!"

The bad:
- is a slow moving tank
- requires good map awareness
- difficult to master
- feint ability is pretty useless (compared to other abilities)
- eats up his energy pool EXTREMELY fast

The ugly:
- is a tank, so cannot do much damage compared to other champions
- very overrated
- usually banned in most ranked games

Depending on your team's output, for Tank/Laning Shen:

Ghost + Teleport usually works well.

Why Ghost?

- able to chase down enemies and finish off with a Vorpal Blade
- can help with taunts to protect precious ally carries
- much better than Flash because even if you Flash away, the enemy will just CC you and you're doomed

Why Teleport?

- able to solo top without the worries of leaving the lane undefended
- extremely mobile combining with his ultimate ability
- best if only one or none of the team has this

In certain cases, if your team has *enough* teleports, you may switch this for a Fortify if no one has this either.

Why Fortify?

- extra damage to minions (+9!)
- can be used after taunting enemies near your turret to kill
- can save a life/turret

For AP Shen:

Ghost + Ignite.

Why Ignite?

- a proper AP Shen will be aggressive and will want to finish their opponent with an ignite instead of foolishly chasing them with his Vorpal Blade
- anti-heal champions, such as Fiddlesticks
- good for soloing Dragon
- better than exhaust due to your burst damage and not DPS

This build will give you a large early-game advantage towards heavily based AD/DPS champions.

Runes:

Greater Mark of Resilience - For extra armor against physical-based attacks (from minions too!) this can save your life.

Greater Seal of Evasion - To be honest, I'd rather be able to dodge the physical attack than tank it (no hp loss!), so this is pretty solid.

Greater Glyph of Resilience - For a double-check on that armor!

Greater Quintessence of Fortitude - Of course, what's a tank without health? You need this for an early game advantage!


Masteries:

A simple 0/21/9 for the best defensive/utility combination. (see above mastery tree for details)

Usage:

If faced against a general rule of 4 or 5 physical based champions, I go straight for this build. You can easily counter their damage and stay in the lane as AD-based champions are extremely aggressive early game. Don't be afraid to use a health potion if you need to, it's better to be alive than feed the enemy team. If you are being engaged very frequently and you are laning with a melee-reliant champion, tell them to back-off and hug the turret while you taunt and Fortify if you can. This will make them low on health and recall, allowing you to farm off their minions and push! The second you see them recall or becomes MIA, you MUST push their tower as Shen is not a fast auto-attacker.

Build:

A fast Cloth Armor and (5) Health Potions.+ (5)
Reason: To counter early game physical attacks and stay laning longer (since Shen can't farm well)

Next, I go for a Ninja Tabi.Reason: Due to an amazing percentage of dodge (anti-AD!), I pick this up to guarantee survivability against AD champs.
Alternative Item: If you are faced with a general rule of 3+ champions with CC, you may replace this with a pair of Mercury Treads.

After, I go straight for an Aegis of Legion.
Reason: This gives your team extra-survivability. Only get this if no one on your team has it.
Alternative Item: You may get a Banshee's veil to counter those odd CC's and some magic resist.

Then, I get a Sunfire cape.
Reason: Extra Armor, also 35 magic damage applied each second to all enemy units around you! (THIS ALLOWS YOU TO FARM CREEPS FASTER THAN EVER!) Shen is not a great farmer, so this item helps a lot with farming.

Next, I get a Frozen Heart.
Reason: To counter their carry as they will receive -20% attack speed and you gain 99 armor as well! A great addition against an AD-based enemy team.

After, I get the infamous Randuin's Omen.
Reason: With an extra 350 health, 75 armor, and 25 health regen per 5 sec, this will make me a beast tank!

Finally, I get Thornmail.
Reason: This is to return back 30% the damage taken as magic damage, plus 100 armor! This is one of the best items against an enemy dps champion. (i.e. Master Yi, Tryndamere, Teemo)

That's it for the first build. Remember, only use this with a strong AD enemy team.

Note: This is a very new build to me, if you find anything you can improve off of this, please leave a comment below! :)

Runes:

Greater Mark of Insight - For magic penetration (with your Vorpal Blade and such).

Greater Seal of Potency - I usually grab this if I'm going all AP, but you can replace this with Greater Seal of Evasion.

Greater Glyph of Potency - For an early game advantage with extra AP.

Greater Quintessence of Potency - With +4.95 AP on each quintessence, I can get up to 3 at level 30. This means +14.85 AP in early game, without any items! That's like a Doran's Ring bro.


Masteries:

This is pretty odd, considering I have never used AP Shen. I do NOT recommend AP Shen, as he should be played as a tank character, not AP. However, it's always good to try something new, ya know?

I go for a 11/9/10 build. (see above mastery tree for details)

Usage:

If your team has a general rule of 4 or 5 AD characters, and they have a tank, you can switch to AP Shen. You can balance it out by getting a large early-game advantage towards the enemy, who are obviously building Armor. Remember, only use this build if you are on a team with little to none AP. Build an early Sheen for the excellent burst damage you need early game. Finally, have an ally (preferably a DPS or AD champion) pick them off while you KS with a Vorpal Blade. (LOL)

Build:

Quickly get an Amplifying Tone and a Health Potion.+
Reason: To build a fast Sheen, and also you will need a health potion to stay in the lane as you will be focused.

Next, I go for Boots of Speed on my next recall.
Reason: Shen is a slow moving champion, and will require more than just normal speed. Also, you will be able to catch up on the enemy, finishing them off with a Vorpal Blade.

After, get a Sheen and maybe a Sorcerer's Boots if I can, if not, I lane once more and on my next recall I get them.+
Reason: Sheen will allow you to acquire more burst damage, and the Sorcerer's Boots with give you further magic penetration while giving superior speed.
Alternative Item: Like the explanation in Build One, if faced with a general rule of 3 or more CC's, get a pair of Mercury Treads.

Then, get a Rylai's Crystal Scepter.
Reason: For an excellent 35% slow and because of the bonus health and AP. I can slow opponents by using my Vorpal Blade and be able to finish them off with my Ki Strike bursts. A must have with AP Shen.

Next, finish the Lich Bane.
Reason: Because of epic burst, speed, and such.

After that, get a Rabadon's Deathcap.
Reason: Even though nerfed (15 AP), it still proves powerful in many nuke builds.

Hextech Gunblade right after that.
Reason: Spell Vamp (almost like life-steal) can help with survivability, combining with Vorpal Blade. I set this to item slot #1 so I can shoot away the runners with little to no health and they will be decimated by my team and/or my KS.

Finally, an Abyssal Scepter.
Reason: Magic resistance for you, lowered for the enemy. You will be invincible with this.
Alternative Item: Again, with too much CC, you may get a Banshee's Veil.
Alt-Alt Item: If faced with alot of AD, get a Randuin's Omen or Thornmail.

Be creative with this build and modify it if you want. Just have fun!

This is an all-around tank build for the common half-AP and half-AD enemy based teams.

Runes:

Greater Mark of Fortitude - For extra health and survivability. (main tank item)

Greater Seal of Evasion - To dodge those tough AD-based opponents. (early game advantage)

Greater Glyph of Warding - To soak up AP-based opponents. (early game advantage)

Greater Quintessence of Fortitude - For an extreme amount of health. (main tank item)


Masteries:

A basic 0/21/9 on masteries. This is a very common and well-used mastery build. (works great!)
(see above mastery tree for details)

Usage:

Your team has locked in as fast as they could, and 4 to 5 of them are squishies, but they balance the AD-AP ratio. This means you must go Shen Tank Mode! This build is a basic build that allows you to become extremely resistant and beefy against all AP/AD attacks in late game. This is a RECOMMENDED build for the all-around tank style.

Build:

Start off with a Doran's Shield.
Reason: For +100 health and great overall armor, plus health regen!

Next, build straight for Mercury Treads.
Reason: This grants overall protection from magic-based champions and gives tenacity.
Alternative Item: Get a Ninja Tabi if you are overwhelmed with AD-based Champion damage. (i.e. a carry like Caitlyn)

Then grab the excellent Aegis of Legion.
Reason: To provide my team with extra survivability and protection against both AD and AP based champions.
Alternative Item: If someone else has this on the team, don't get it. Replace this with a Warmhog's Armor if you need to.

After, get a Sunfire Cape.
Reason: Faster farming, extra armor, and 35 damage each second in magic to all enemy units around you!

Randuin's Omen is next.
Reason: Extra armor, more health, and an extreme amount of health regen! A must have against those AD-based champions.

Depending on the situation:

If you are getting nuked like crazy without or with little CC, get a Force of Nature.
If you are constantly being stunned, slowed, etc while in teamfights, grab a Banshee's Veil.
Then get whatever is left in the list.

Shen isn't the greatest farmer in the game, and is usually because of his relatively slow attack speed. However, there are ways to successfully farm with Shen.

Tip #1: ALWAYS last hit minions. (with or without your Vorpal Blade)

Tip #2: Build a fast Sunfire cape. (situational)

Tip #3: You may not need to last hit if you have Ki Strike, but it should be saved as a burst attack towards the enemy while laning, while using Vorpal Blade first for the life-tap.


Remember, do NOT taunt enemy minions as this is a waste of energy. The ONLY exception is that you are trying to save a turret that is swarmed with minions. The energy should be saved for Vorpal Blade tosses. (for the last hit kills)

Shen in team fights is pretty sweet. You could save that Akali of yours (or whoever is being focused) by taunting the DPS champions and nukers. Also, if Fiddlesticks is channeling his ult, you can taunt him to cancel the channel and cause him to have his ultimate on CD.

It should be something like this:

Use your ultimate on a squishy being nuked/focused.

Taunt as much enemies as you can upon arrival.

Ping the enemy you want focused for your team to focus on.

Toss a Vorpal on the focused person.

???

PROFIT!

Don't be afraid to call "b" when you need to back. Your team will thank you and will agree.

Just don't feed, and protect the squishies at all costs! AND THAT AKALI!!!

Shen is overall an extreme tank that has many supporting features to help the team.

Whether you choose to become an AP Shen, Main Tank Shen, or whatever, you must remember not to feed and save as much teammates as you can. Your life is not worth as much as the AD carry or AP!

I hoped you enjoyed my rather simple guide on Shen, as this is my first. I'm setting this as "Comment to vote" so people don't randomly downvote it because it's my first.

Also, please upvote if this build/guide helped you! ^_^

IGN: Prince Farming

Contact me: that_one_idiot@yahoo.com

Thanks~!