We currently have a lot of synergies at our disposal that we need to utilize to be mana efficient and I would like to share and discuss my findings and others findings and opinions.
First and far most, our "go to" spells. With the talents Daybreak and Infusion of Light, we get a synergy for using Holy Light, Divine Light and Holy Shock. This should be our bread and butter of efficiency. HS procs infusion for -1.5 second cast time on HL / DL. HL / DL procs Daybreak, giving us a free HS off the CD. This is our bread and butter. This also generates a large amount of Holy Power allowing us to use WoG, a basically free heal, that has a 20% chance to not use holy power with talents or a LoD to heal the group. Granted LoD is hard to use most times, it is there to be utilized to heal the group.