As Arch covered build, I will talk about skills
The winning move for combat are 4 skills that are quite handy
1) Silence (blast)
2) Insta-cast (Sutra, but eats 2 fury)
3) Teleport-ish (Can't remember, but is something from earth tree)
4) Every earth skill.
I've asked around guild members, and I find that Earth is the weakest, even with me, and other mages (except when using earth shield). So if you are in sutra, you should, no, YOU MUST beat anyone else with earth. Combat is usually bad, since almost any melee opponent, will run at you before the match starts, so you'll be in the losing hand.
That's when teleport kicks in. I overlooked this skill, due to it's lame distance on lvl 1, but eventually, I learnt to live with it. It's a life saver, when a melee gets too close, turn back, run for less than 1 second and cast it.
In TW, and open fields, you get better chances, as you can slow them, and beat them before they even reach you.
Hunters are insta pwnage (you get killed btw), other mages, is just a "who cancels the other on time" kinda thing and who deals more damage (of course, you won't cast something of the same element as the shield they are using, if they have water shield, then DON'T use water).
And, for WF. I just discovered that Phoenix kicks the pet back. So you can Push+slow, then cancel the cast of the WF, beat her a bit, then, if the pet is coming again, teleport-ish, slow, push, keep doing this until you win (or the pet owns you).
And, as a final tip I would recommend you build your 1-6 bar, and F1-Fx bar with a logic sequence of skills for pvp (maybe use another row for it). With the Earth skills on 1-2-3, for easy access, and the other useful things, like slow and phoenix.