For PvE, you'll generally use no totems and just blow stuff up.
This is because you have Water Shield on each of your casters.
One nuke or maybe two per shaman, is all that is needed to kill your target.
You use almost no mana with several toons.

For more difficult mobs you'd definitely employ a castsequence for each shaman.
You might have more then one setup of these.
For example, in an instance you'll have Stoneclaw totem to deal with adds... Perhaps two on a click, and two on another click.
But outdoors, Stoneclaw is a pretty useless totem to be in a cast sequence.

Some totems are very important, and you'll want to access them immediately.
They can appear in your cast sequence, but you'll want to be able to get them now.. without needing to go through the sequence.
Typically this will include:
- All groundings now.
- Staggered drop of Tremors.
- Fire/Earth Elementals.
- Mana or Healing Totems.
- Cure Totems.

Your sequence should include a reset command, which will reset the sequence after a certain time period.
This allows you to dump one or two totems per shaman, without dropping number three or four.
Or if one shaman is stunned or otherwise unable to drop a totem, the sequence will re-sync shortly.
I like reset=12, but you can use reset=target (resets when you change target) or reset=combat (resets when combat ends) or even reset=modifier key (resets when macro is clicked with the modifier key) or any combination.
You might have Mana Spring as the first totem in each shaman's sequence in your PvE set. So one click only, is mana totems.
A PvE sequence might be:
--- Mana, Grounding, Tremor, Searing
--- Mana, Tremor, Grounding, Searing
--- Mana, Grounding,, Searing
--- Mana, Grounding,, Searing
The fourth click is searing totems, so when you don't want adds three clicks gets your non-aggressive pulling totems out, and a fourth click gets totems that will pull anything nearby for you. If you have Wrath of Air or Totem of Wrath, for PvE they'll be in your rotation for sure.

With four shaman's, your tremor will be
--- /castsequence Tremor,,,
--- /castsequence ,Tremor,,
--- /castsequence ,,Tremor,
--- /castsequence ,,,Tremor

You'll definitely want this on an easy to reach key. You might put two Tremors in a normal cast sequence.
But even if you do, you'll want this too.
Basically the Global Cooldown on totem drops is 1 second.
So with a Fire/Water/Air/Earth, four totems dropped per shaman.. each totem is about 1 second after the last.
Tremor pulses every 2 seconds.. so the best you'll get is a pulse every second in a castsequence.
But with the above macro, on say 4... you can mash 4 quickly (ideally 4 presses over 2 seconds), so Tremor pulses every half-second.

You'll want to drop all Groundings on a key, just for when you have casters against you.

A cure-set might be...
--- /castsequence reset=10 Poison Cleansing Totem, Disease Cleansing Totem
--- /castsequence reset=10 Poison Cleansing Totem, Disease Cleansing Totem
--- /castsequence reset=10 Disease Cleansing Totem, Poison Cleansing Totem
--- /castsequence reset=10 Disease Cleansing Totem, Poison Cleansing Totem
The first click cures two poisons and two diseases from the whole party.
The second click cures two more of each.
Third will be two more again, as the sequence is over and it will start at the beginning.
If you don't need to cure something *now*, just leaving a single click will gradually cleanse you of poisons/diseases every few seconds.