As a fellow tank, here are some thumb rules for easier tanking.

1. Mark monsters. You can also tell them to focus what YOU are targeting and it usually works better than marking.

2. Tell the healer to not overheal you and never use anything above Cure I unless necessary.

3. If the DPS ignore your focus, are doing more damage than your Enmity generation make sure to tell them what they are doing wrong. If they keep ignoring, let them get enmity and die, this works like a charm with any DPS who thinks they are entitled to see big numbers and ruin the teamwork.

4. Single target WS that generate enmity are more effective than flash for generating enmity. You should be flashing only when there are 3 or more mobs and do so at a rate of 3~4 WS, this will clear Healer aggro and DoT aggro from Arcanists.

5. Put points into strength every so often.