Im no Shen pro or anything, a friend of mine just asked me what build I'm using on the new Shen.
So here it is!

Yes, I started playing him as a jungler but soon switched to toplane.

I have played numerous games on the reworked Shen (about 15) so I obviously know what I'm talking about.

These days everyone thinks they have to carry the game themselves. People always pick carrys, and the teamcomps basicly become really bad. To counter this I've started palying full tank top/junglers to play more team oriented. And it's worked out so far.

This build focusses a lot on global map presence by getting 40% CDR, putting your ult on a little more that a minute of cooldown (72 seconds). Using a mastery and the right boots you can also get 40% CDR on your summoners (!) putting your teleport and flash on 180, 180?, YES 180 SECONDS OF COOLDOWN.

It might be a good idea to duo with someone that plays a carry role. You can ult him constantly and protect him in teamfights. It will be a great benefit to your team.

Obviously Teleport for the map presence. Just ulted bot lane and your tower is getting pushed? Teleport. Ult on cooldown and mid lane needs help? Teleport.

Secondly Flash because.. Flash.

6 Ferocity -
That little bit of attack speed and sustain. Really sweet on Shen.

6 Cunning -
Extra movement speed to get to fights faster and that little bit of damage for top lane dueling.

18 Resolve -
I'm a huge fan of Runic armor together with Grasp of the Undying. It gives great lane sustain and it improves the shields Shen gets constantly from his passive.
Insight (15% recuded summoners) is really key here.

The Starting Items

Your starting item basicly depends on your lane matchup.
VS AD Threat = Cloth Armor / Doran's Shield
VS AP Threat = Ruby Crystal / Doran's Shield
VS Low Threat = Boots
Always spend the rest of your gold on pots and don't forget your trinket
WAAARRRDDDDD!

Getting that juicy core build

Your first item also depends on your lane matchup.
VS AD = Sunfire Cape
VS AP = Spirit Visage / Locket
VS High AD Threat (yasuo/fiora) = Early Thronmail [They'll never see it coming... suckers]

The Core of the Core

Lucidity Boots with Distortion. I'm telling you. It gives you an easy 10% CDR (CDR is hard to get on Shen), and also 10% CDR on summoners.
Distortion gives you another 15% CDR on Flash and Teleport, and gives you a nice speed boost on using those summoners.
I sometimes even get this item as my first item.

Building Further

Get Ohmwrecker if they have a lot of AD damage. It's a pretty goot item on Shen. It's the only armor item that gives CDR without giving mana. The speed boost is also pretty good on Shen.

If you're not picking the Ohmwrecker, get both the Spirit Visage and the Locket. This will get you to 40% CDR.

Build appropriate tanking items vs the enemy team...
Enemy ADC got fed? -> Thronmail / Deadmans Plate
Enemy APC got fed? -> Spirit Visage / Locket / Banshee's
Enemy **** the bed -> Titanic Hydra / Frozen Mallet

You're going to want to max Q. Q is your main source of damage.
Leveling W is only going to reduce the cooldown, and not by that much. I'd suggest maxing it last.
Max E second for shorter cooldown and more energy regen.

Level your ult when possible.

Just play safe, farm under turret with Q. You probably won't win the lane, but you will also not lose the lane. Look for saves at other lanes. Use your ult a lot and TP around the map. Get that global pressure going. Try to win your lanes by getting a lot of ganks.

Good Luck!