It takes nerves. You might have to strap into a safety harness and ride a lift 120 feet up or lean in as close as your safety advisor will allow to a welding flame.
It takes timing. The right time may not always be sunrise or sunset -- the sweetest light can happen after a storm or even just between passing clouds.
It takes vision. The difference between a good artist and a great one comes down to his ability to capture light and angle and composition on set, then follow through with magic in post production.