So far I've been switching off and on with a DK between main and off-tanking Naxx with my guild.
I've noticed that my damage mitigation is fine, but my threat on trash and some bosses is not lacking per say, but not as good as it could be.
I basically took a build off wowwiki, and beyond that have used common sense to figure out a rotation and what gear to choose.
I'm really interested in hearing some opinions and what I should do to become a better tank. I'm mostly interested in knowing a good rotation, possible a better build and what glyphs, gems/enchants to use to maximize threat building while keeping a good amount of damage mitigation.