ok. The first thing is Pure healers are squishy. Keep this in your mind. Unless theres a prot monk to cover yer butt you wont hold much damage specially if you are using full tats like I do. However all is not lost! First things first. Don't invest in protection throw that out the window. If you want uber healing go all heal, divine favor and some on your secondary to complement. In my case I play Mo/Me so Im hitting arenas with what I know healers of the Mo/Me kind can do best: Namely hex management and energy management.
So with the prot and such out of the way lets pick up four 5 healing spells. That's right Word of Healing is a must and so is Dwayna's Kiss. Next there's four slot opens. I tend to take always the follwing: Inspired Hex. Its good hex management AND energy to boot. Next is a matter of taste. I normally take Divine Boon to spike powerful heals AND fuel Contemplation. I take Contemplation to further manage self healing and hex management. Finally Holy Veil if you want to further increase your hex removal capacity as well as having another nice enchant to cover you up and fuel Contemplate.
At this moment I tried testing with Channeling but this skill is best left for the prot booner who can be much more daring... instead of the squishy healer who has to be away from enemies.
Now once you have your healer heres the most important things:
First off make sure you join up in Team Arenas, and with a good offensive team that knows their game. The faster the enemy dies the less at risk you are. When I play this build I usually play with three rangers, or three mesmers or other nasty combos of the kind (Lich Necro, Axe Warrior, IW Mesmer) or spikers.
Second AND THIS IS MOST IMPORTANT: MOVE YER ASS. RUN. NEVER EVER STAND STILL except to cast a heal and self heal when needed. Always keep in movement.
Third and this one ties with the above: DO NOT RUN AWAY FROM YOUR TEAMMATES. Ok so you are under fire and sheat we know Ive been there BUT RUNNING away from your team is worse. You open yourself to letting them die and ultimately yourself since you have no backup. Therefore I tend to weave in and out running circles around my teammates always on the move.
Fourth when fighting Rangers TAKE COVER. Sure they interrupt as hell. But that doesn't mean they are infalible. Takinc cover, moving away from them and putting something in between helps a lot, specially since your spells can reach yer teammates.
Fifth hex are your friends IF you know what you are doing. They provide your energy with Inspired. Not only that but with this build Dwayna's Kiss booned and while target is hexed is amazingly effective. Also Holy Veil then Kiss then remove veil is awesome for this matter.
Sixth don't get frustrated. This is important. You are SQUISHY you might die depending on the field and enemy. Don't panic. Await rezzing and be prepare to unleas a Word and run like the dickens again. I normally unleash a Word and run then boon and self heal if need be while running to regain energy.
Yeah this all sounds complicated. But hey no one said being the doctor in the battle field was going to be easy.