As a warrior a few tips I'll share.
For single target threat I always start with a shield slam and then spam my macro till shield slam is off cool down or sword and board procs to make it available.
Whats the macro?
/cast heroic strike
I keep a regular devastate on my bars if I run into low rage situations, which is almost never on heroic bosses in ICC.
Also key bind Vigilance and Intervene. When someone is riding my ass on threat I hover over their raid frame and hit the bind. Changing Vig during a fight to higher threat targets and intervening them when applicable is a huge help.
Ive posted this before and had many respected community members agree with me here: http://www.tankspot.com/showthread.p...s+to+all+tanks
The facts about Expertise and Hit in the current game.
Look its not that Expertise and Hit do not increase your threat, they do. However they do so on a much smaller scale than people realize.
How all tanks generate threat (Listed from the highest source to the lowest):
1) Using your abilities properly. This is paramount, nothing increase your threat more than this.
2) Spec and Glyphs.
3) Proper use of external abilities such as TotT and MD.
4) 26 Expertise Skill.
5) Hit rating.
There is something so appealing about backhanding someone across the face with a shield.