Midday
We chose locations so a viewer's attention will be naturally drawn to the model. Diffuse light enhances skin tone so we almost always want the model in the shade. We want to enhance the dimensionality of the face and shoulders so we need sharp light drop-off. The softness or sharpness of the nose shadow will allow us control the mood of the image. The bright cheek of the model should be the brightest parts of the image so backgrounds should be darker than the bright cheek.
We choose locations so we can control the brightness, saturation, contrast of the model. The brightest object in image is the model's bright cheek. No mirrors, bright objects, or electric lights in the background. The wardrobe should be richly saturated. And the sharpness of shadows of the nose, eyes, and north will set a mood.
Where do we find all this?
Narrow, east-west alleys with low buildings on the south side turn the buildings on the north side into giant reflectors while the buildings on the south side shade the model.
South or west facing deep doorways, doorways with awnings, or parking garages turn the pavement into a giant reflector and provide a sharp shadow line.
South or west facing windows in coffee shops, restaurants, bars, ... with dark and poorly lit interiors.
For Fun Vallejo Steps
Scouting
I know many locations in the Bay Area that work well and we can discuss them in our initial meeting. I always want to add new ones. Please suggest what you think might work. I will explore the building height and walls as backgrounds with Google Maps. Using PhotoPills I can see approximately when the sun will illuminate the walls.
If your suggestion looks promising, I will visit it at about the same time we would shoot. The PhotoPills augmented reality feature will show me the hours the sun will be above the rooftops on any given day. I can also observe and measure the light and color cast.
You are always invited to scout with me.
Golden Hour
The cliffs and beaches along the coast are ideal because the sun sets behind a natural horizon. All of the San Francisco Gun Batteries are ideal. Each has large concrete walls and clear views of the horizon. Each of the 24 Nike Missile Sites in the Bay Area has a clear view of the horizon. Most are along the coast but some are on the ridge line in the East Bay. Sutro Baths has some structures that work well for backgrounds as well as a fun cave. The parks along the East and South Bay work well. They are far enough from the mountain ridges that separate them from the natural horizon and they closely approximate a true Golden Hour.
Here's an East Bay Marina just before Golden Hour, SFMOMA, The Sycamore bar and three street scenes I would like to try, Cow Hollow Starbucks, Civic Center BART, and 24th St at dawn.
Nighttime
If we shoot an hour or more after sunset, our light will be from bars, restaurants, streetlights. We will choose a street such as Broadway, Mission, Valencia where we will find many bars and restaurants and work with window lights to create a mood.