Well, during the Southern hemisphere winter, the light is actually pretty nice all day long. During the summer, I definitely shoot for the normal two hours before sunset. But the more I learn about artificial lighting, the more I like trying new things. Not enough light isn't usually the problem. Off camera flash is easy enough to use to fix that. It's direct sunlight that is the most difficult to work with. In that case I try to play with the harsh lighting and the shadows, I always bring a reflector and then recently have started using flash composites to "kill the daylight" as Ryan Brenizer said when he explained the technique to us.