I really hate using thunderclap on pretty much any pull. In my opinion it takes too long to switch to defensive stance after, it cost a lot of rage, and also does very poor threat. Finally if you have any damage reflection gear the attack slow not only lowers the amount of rage you will have during the fight but also lowers the amount of threat you will put out.
My preference is to charge/bloodrage and use one Battleshout or demo shout to get everything focused on you. Shield slam or sunder skull then start applying sunder on everything you can while tab/cleaving.
If you don't have a lot of rage ignore the cleave and focus on tab sunders. Save your taunt for anything that breaks off towards a healer or cloth dps. Keep mocking blow in your pocket for taking a mob off of a healer.
Depending on how many mobs you are tanking either tab/cleave and spam demo/battle shout or tab/cleave and spam sunder.
If you know you will hit your entire group with Battle shout use it instead of demo shout as it will cause more threat.
Ideally on a large AOE pull where you will have your party in range I like to open with the following: Battle shout and start tab/cleaving while applying 1 demo shout, then go back to spamming battle shout assuming you have your 4 party members in range. As mobs start to die begin working in sunders instead of using a shout.