Shadowstep/Shadowdance Ambush

Let's face it, the whole Subtlety tree is based around doing as much damage with Ambush as possible:
Opportunity, Serrated Blades, Initiative, Improved Ambush, Deadliness, Sinister Calling, Waylay and Slaughter from the Shadows all directly affect this.

The play of this build focuses around both Shadowstep and Shadow Dance followed by Ambush(es).

With 5 points in both Sinister Calling and Deadliness to increase Agility and AP, combined with Opportunity, Improved Ambush, Master of Subtlety and Lethality it all adds up to some sick Ambush crit damage. You should have 4 or 5 Dots on your enemy after the initial Shadowstep/Ambush to (improved) eviscerate them for further major damage.

Essential macros for this build:

Premeditation/Shadowstep macro to gain you two free dots.
Shadow Dance macro that allows you to access your stealth tool bar.
Ambush/Use Thistle Tea for nasty repeated Ambushes.
Weapon swap macro between dagger/sword for your ambushes and your sword/dagger for more Hemorrhage damage.

With some decent gear, this build is good for farming Honor in battle grounds. Focus on taking out cloth/leather wearers, or more heavily armored classes that are low on health and straggling on the edges of the battle.

Throw in the Ambush Glyph along with crippling poison on both weapons and it virtually guarantees you the most killing blows on the field.

Enjoy.