As long as your fish feel secure, are large enough and are well fed they will spawn. A large tank and cave helps with spawning but the females also need places to sit out when holding as the other females will harass them. I usually use large half flowerpot caves at each end of the tank with an empty central area for fish interaction and feeding. I keep Frontosa species tanks since I am specifically breeding. Some people place a flat raised rock so the male can perch on it and see all around to know he is secure but I dont. Some people keep the tank half covered and reduce foot trafffic around the tank. They can be flighty fish and dont like sudden surprises. Since I do want fry, I rob eggs a day after spawning and artificially hatch in glass egg tumblers. Frontie eggs are large and very delicate for first 10 days so I use the same hatchers as for Arowana which also have huge eggs. I prefer to hatch because i find letting females hold naturally greatly reduces my fry numbers and females lose a lot of condition and my next breeding cycle is delayed. Hatching frontie eggs has a large learning curve so this may not be best for you. The larger and older your females, the more fry and confident she will be at breeding. My most productive females are about 10-12 years old.
My fish are used to a spawn cycle so I can trigger with a fast then a generous food cycle (prawns and earthworms) and then large water change. I deliberately withhold feed and waterchange until I want to trigger the spawn to make the difference more significant. Females will generally spawn within a few days of each other. On one of my colonies I need to keep a small insignificant male to make the dominant male less lazy.
I think there are specific Frontosa forums online if you want a lot more detail.