Being well-geared shouldn't be a problem. Sure it reduces the amount of healing you need, which again reduces spiritual attunement mana gains, but better gear (ie. higher avoidance and block) also increases your mana gains from BoSanc, and lets you pull more trash. Unless you're already dying to packs of mobs regularly, one of the easiest ways to deal with mana issues is getting more angry NPCs to beat on, and hopefully miss you.
That, judging wisdom and trying to keep divine plea ticking (ie. push forward so you can attack something new before DP wears off, or wait with a new pull until it's close to cool down) should take care of your mana, if you still run out, drop consecrate from your rotation temporarily. I also carry mana potions, they're not necessary but can save your rear if you screwed up and end up OOM and with DP on cooldown in the middle of a freshly spawned pack of mobs.
To stack the deck in your favour, read and understand the resources available here and on
Maintankadin, gear accordingly, set up your UI so you can easily do your 969 rotation and reach utility spells, practice rotations on a dummy, and learn or review tactics for bosses and trash. But to learn "tank awareness" you'll have to go out and do it, even if it means you wipe due to tank errors a few times, or people die during the first runs because you're still getting the hang of helping your party with taunts, salv or HoP.