I try to pull with charge on a target, then tab and throw on another while charging, back to the main target and shockwave, thunder clap, shield slam on main target, tab revenge, demo shout and using cleave all the time, always moving around in circles of the mob so shockwave and thunderclap can do the job right.
If there is a caster far away keep shield reflect up all the time, if there are 2 casters, save heroic throw to interrupt one so it comes to melee range.
Try not to stick on thunderclap and shockwave. Demo shout works too, and of course, always use cleave. In time, you will find out that AOE tanking is fun.