When consulting with my clients I stress the importance of time of day & lighting, it can determine not only the quality of the image, but also the mood.
When shooting I like to use both ambient and strobe lighting. As you can see in the photos above time of day can change the entire feel of a photograph, where the first image gives a Miami by the beach feeling, the last gives a more sleek feeling.
When you are dreaming up what type of portrait you'd like time of day is a big deal! No matter what the time I am well equipped to help you achieve your vision.