Plan around the two generators
On Ashfall Caldera, contest the Turinium generator you can reach and hold, then pressure the second if the first is secure. The official Ashfall Caldera map walkthrough identifies one generator on each side of the map. Those positions matter when you're pursuing a score victory, so an early push straight into the central crater can leave you fighting far from the objective.
Use high ground to cover the crater lanes
The middle of the map is a large crater with four hills and narrow gullies between them. Put turrets on the hills or crater rim where they can shoot down into lanes. If you're attacking, scout the high ground before sending direct-fire troops into the gullies. Artillery can shoot over terrain, and air units can approach across terrain that blocks ground movement.
Choose an exit or take the long way around
Expect defenders at the narrow ramps out of the crater. Concentrating on one exit gives you a chance to clear it with enough support. A perimeter route can avoid the inner crater, but opponents can still hold the approaches near their HQ behind cliff walls. Plan a fallback route and keep pressure on the generators while your assault force is tied up.
FAQ
How many Turinium generators are on Ashfall Caldera?
The developer walkthrough describes two, one on each side of the map.
Where should I place defensive turrets?
The hills and crater rim overlook the narrow routes below and make good candidates.
Is the perimeter route open all the way to the enemy HQ?
The outer route avoids the inner crater, but cliffs create choke points near home regions. Scout those approaches before committing.