Two of my favorite times of the day for portraits are sunrise and sunset with beautiful golden quality light that the sun produces. Just before sunset, it can get tricky to balance the exposure for both the foreground and the background. Expose for the foreground, the background loses detail. Exposure for the background, you subject becomes a silhouette. Enter off camera flash; which allowed me to expose for the background and bring up the exposure of my subject, the two young ladies, which produces dramatic portraits. Here is the result for a portrait session in Key Biscayne, Florida:

A little extra touch I added, was the sun peeking through the sunglasses.