For me, an aerial picture is no different than a close-up portrait. It's a question of framing and angle. Helicopters are great for that. But I've also used planes. Of course, I always have a harness.
After Hurricane Katrina, over New Orleans, my helicopter crashed and the pilot and I were only saved because we fell on the roof of a flooded house that absorbed the shock. When the helicopter was spiraling downward out of control, I didn't expect to survive at all.