Avoid Squintface
When shooting photos outdoors, portraits or otherwise, most people have their subjects face the sun so the photo can brighten the face. The problem with this is that the sun makes people squint, so the faces are well lit, but they’re squinting into the camera.
No outside photos at lunchtime
It’s also a problem when the noon-day sun is straight above your subject because it will create what photogs call “raccoon eyes”. Unless you have a flash-fill, avoid taking photos at noon.
Expose for skin
Now, if you just shoot into the sun with auto exposure, the camera will expose for the the bright areas, in this case the sky. In this case, we have a nicely exposed sky but our subject is in silhouette.
More light can lose detail
We need to keep detail in the sky and light up the subject without having them squint and without over exposing the sky. Opening the iris (f-stop) is a solution but you can lose detail in the background.
Turn your back to the sun
The quick solution is to have the sun at your subject’s back, expose for the sky and use flash-fill. Forget using an iPhone. The flash on the iPhone can not compete with the sun unless you are three feet away from your subject and sometimes it still isn’t enough. You can use the built-in flash on the camera, or better yet, use an external.
Having the sun behind your subjects at 45º angle creates texture and a rim of separation as seen in the model’s hair above and the family portrait below. Ideally the best time of day is right after sunrise or just before a sunset. Production people call this “magic hour”. It’s when the sun is at 45º, adding a warm, rich light.
More examples at magic hour. Sun is at 45 degrees to the left and external flash set to just fill the subjects.