• Get level 8 Marauder
  • Get level 8 then 15 Conjurer
  • Use skills in combos (Fast Blade -> Savage Blade + Repeat)
  • Focus on generating at least a small amount of enmity before using damaging cooldowns & DoTs
  • Use defensive cooldowns in succession. Not all at once.
  • Weave defensive cooldowns in-between attacks.
  • Defensive cooldowns do not break combos.
  • Provoke is NOT for generating enmity, use it to catch a stray when you've lost aggro

I'm still levelling, but there's so basic tips I wish I knew at the start.
Overall tanking is quite simple.
If you're as geared as the dps, you'll find yourself having fun.
If you're level synced with nicely geared people in a new dungeon, you may want to spam Flash more often, and ensure target numbers are up before engaging.

Final tip: WATCH OUT FOR HEALER ENMITY! It's a lot harder to track on the initial pull than DPS'. (Spam flash 3 times to give a buffer)