Shield Slam > Devastate > Revenge would traditionally give me about 900-1000 of threat off the bat. Would be more if I have higher SBV I think but that's enough to cement the mob onto me.
Bloodrage before the mob arrives and hit Shield Block. It'll light up Revenge indefinately. If there's a second warrior in the group, I'll ask him/her to sunder to help me with the threat generation. We would altenate with me throwing Devastate first and then he/she will throw sunders after every Devastate. Works quite well.