The brighter it is, the more you need your flash.
Huh? That sounds counter-intuitive?
Not when you think about it. Bright sunlight means harsh, contrasty sunlight. Contrast means that part of your picture will be too dark or too bright.
Here is Sedona, AZ, last week:
Not bad. But can you see how dark the foreground is?
“But you can use exposure compensation, Mike, plus one or two stops”, I hear you say.
Yes, but then the entire picture goes brighter, so the background would be all washed out – too bright.
So the only way is to turn your flash on. And now you get this:
And that is why you should always carry a flash – even on the beach, even in Mexico, and even in Arizona. The brighter it is, the more you’ll be likely to occasionally (or more than occasionally!) need it.