Very Useful Trial Healer Builds (focusing on Warden, Templar, NB and occasionally Arcanist.: Situational Healer for Prisons and Tombs - Построй PvE - ESO

Trial Healing 101

If you're wearing Spell Power Cure + Pillagers Profit aka “SPC-Pillagers” - that makes you the group “Kite Healer.” 

If you're wearing Roaring Opportunist + Jorvuld's Guidance aka “RoJo” - that makes you the “Group Healer.”  

As the names of these two healing roles imply:

The “Group Healer” focuses almost entirely on standing just behind/outside the main DPS group while providing tons of Area of Effect (AOE) heals, DPS Damage Buffs, and Resource Restoring Synergies to the main group.  

The “Kite Healer” role is a little bit less well defined and changes depending on the trial, and the make-up of the group. 
In trials where enemies throw attacks or jump to the furthest member (think: The Capitan in vKA or the Saints in vAS) the Kite Healer is usually responsible for “kiting” that attack or enemy so it doesn't hit the rest of the group. 
In fights where there are no mechanics that require kiting, the Kite-Healer essentially becomes a source for Barriers and War-Horns - as well as a source of burst heals for the group, especially tanks.