In the interest of giving mages some additional build ideas to play around with, I'm linking the PvP build I've been using for a long time now. I can assure you it's very useful, but it's anything but faceroll, requires a lot of attention, and could be a really bad spec for low rank (I used this post-rank 6 only - if you're looking for an entry-level spec, something like Chlor/Dom or Chloro/Lock is probably better.)

Some of the point placement is pretty arbitrary (I'm always forgetting to even touch Reflective and Arresting Presence even though I have points in them) but the point totals are there for a reason (34/12/20).

The basic idea against single-targets is: Squirrel > Storm Shackle > Life Leech and Withering Vines (from the increased cast time) > Dark Touch > Neddra's Grasp > TI + Transference if necessary > Do everything you can to ensure the enemy doesn't outlast TI + Trans - Quick cast time or Opportunity proc + Split Personality can be a big help > Watch debuffs carefully and cleanse if needed > Bloom when low > Reflective Command against casters. And so on.

Basic idea against groups is:

1) Plant TI on the players least likely to be watching debuffs (spamming Marksmen, spamming Warriors) and/or players who are least likely to be far away from others.

2) Use Transference + Incompetence + Mana Wrench on healers when the opportunity arises.

3) Use Transmogrify and/or Death's Edict and/or Storm Shackle to slow and harass melee or stop someone at low health from running away. (Hint: With the increased cast time, you can squirrel one melee and use the speed to quickly Death's Edict another - assuming you aren't running into IMMUNE spam).

Note that the above examples are by no means exhaustive or come close to covering every tactic I've tried. I've been playing this spec roughly since rank 6 (I'm rank 8 now) and I still miss out on very useful tactics all the time. The sheer number of possibilities is part of what has kept me interested in this spec. Naturally, however, I have fallen into certain routines for maximum decision-making efficiency in the heat of battle.

Have fun guys. Creativity is half the fun of PvP.

Plus, watching warriors movement spam with Storm Shackle on them is just priceless.