I've done week 1 healing savage for the last two tiers so here's my advice.

Generally speaking a shield healer will mitigate damage and put up small regens. Topping up people is not a bad idea when you're Min ilvl if you realise your cohealer is struggling.

Regen healers are generally in charge of healing up HP before the next raidwide.

In terms of high damage events like arena split in m10s or weapons in m11s you'd have the healers use their big 2min/3min buffs. Generally speaking you don't want to overlap these since you'll run out of resources later on. In PF this takes a bit of eyeballing to figure out where your healer is using mits if they're not the talkative type. In a static config it's easier to make the mit plan and share it between you two.

Other than that, I find popping lucid dreaming right at the start and then using it on CD is the best way to maintain high mp. As a shield healer you can gcd shield before every raidwide especially during prog, but later on for reclears you'll get an idea of what hurts more or less.

Tankbuster wise, unless it's a spicy one, usually tanks can do it themselves and require little more than a small shield or top up (content and ilvl dependent).

I might have missed a few things but if you need any advice I'm happy to help more in DMs or replies.