PROS:

global ult

save teammates lives

Great survivability and sustain

Tanky

good escape

good ganks

very good utility/support

CONS:

Energy based spells

low damage

average jungle clear times

teleport ganking

Joining teamfights when your ult is on CD

good ganks

average clear times

Tips for better jungling.
-Use Feint after you just used Ki Strike for a faster recharge time
-When you have almost slain a creep and Vorpal Blade is off cooldown, use it on the next creep instead.
-When low on energy note that Vorpal Blade's duration is longer than it's cooldown. Wait before tossing out an other until the duration has timed out.
-When invading the enemy jungle, be sure to keep enough energy in reserve to Shadow Dash away, and always know where to escape (preferably through a wall)
-Keeping some energy reserve is always a good idea, especially when you may need to save someone with your Ult, so you can actually do something once you teleport to them.
-GANK! Shen is an awesome ganker so let your enemies know that. You should be that Ninja that could be anywhere on the map!

The Seals and Glyps are standard for most junglers but the marks and quints might need some explanation

Mark of Attack Speed: These are mandatory for jungle Shen. Not only do they allow more Ki Strikes, giving you more damage and energy gain, they also work well with the passives Madred's Razors and Wit's End.

There are essentially 2 different tools Shen can use to farm. His basic attacks (empowered by Ki Strike preferably), and your Vorpal Blade. In an easy lane you should be using Vorpal Blade to poke the enemy, not to farm. Make sure to conserve energy as best as possible.

Well folks, I hope you enjoyed and got a lot out of this guide. If you have any questions, criticism, or comments leave them in the comments, I'm looking forward to your feedback!

I'll be updating the guide regularly, no worries!

Good luck out there everyone, and I hope my guide has helped you in one way or another!