Actually a better method than turning down the persistence on a Billowy Advanced Perlin is to simply add in a Blur filter and increase the amount until it looks right to you. This way you still maintain the height variation but it's smoothed out a bunch. You can also clamp the blur if you only want it to only affect a specific height of the terrain. For my use, I clamped it to the lower region only to get rid of the "potholes" in the terrain but keep the detail on the top of the hills:
It looks like it would mostly be characterized by smoothly rolling hills and generally flat character, is that correct?
My first stab would be an advanced perlin noise device set to Billowy noise type, scaled with decent feature size, and turn the persistence down until the result is fairly smooth. I would then adjust either the elevation center/steepness controls, or use a Clamp device to limit the heights so that the peak to valleys are very gentle.