Advice for starting PvP healers?

[tinythinker]

Hello, I've seen a couple of complaint threads about healers, but does anyone have advice? (I play WHM and SCH)

Looked up info elsewhere. Most is outdated except (for example, Cleric Stance is now disabled) for a great thread from last month that focused more on Astrologian but still had good insights for all healers. I wanted to try PvP when I started playing FFXIV last spring but it was kind of slow getting through the queue. I did find some helpful things out from my web search (including some clever SCH macros) there but additional insights are very welcome. Tried Shatter once last night and... ouch.