Paying attention to the existing light will give you your first clue. Lets take a look at the following photograph and I'll explain my process and choices for doing what I did. I have photographed in this same location several times, this time I remembered to shoot a set up to share with you.
When I look at the scene before me, I see a long bank of window which I can use as a out of focus as a design element as my backdrop. With the windows on the right side of the frame, it makes sense to me that I should light from the same direction. Doing so allows for a more natural looking light, basically duplicating the lighting pattern that exists.
Lighting choice are many here, I could place my subject in the hard light of an open window if that were the type of light I wanted. I could perhaps place a silk over the window and use the sun as my light source, the silk would act as a large softbox producing a soft quality light.
Space permitting, I could assemble a large softbox or just bounce my light. The day I was photographing, this company was having their board of directors meeting. There was a lot of traffic around the executive floor and the choice of a softbox would just impede movement through this narrow hallway. Bounce was the right choice, and as you can see, look quite natural.
In the photo below you can see the actual setup, I aimed the flash high on the wall about the same height I would have placed another modifier. Special notice should be taken when looking at this photograph. I have a flag or gobo on the far side of the flash, this prevents the light from the flash directly hitting the subject. I want all the light reaching my subject from the bounced subject. I bounced my light on a section of wall between two windows.
On this particular day, I had 3 additional lighting setups on the executive floor. You can see a small card taped to my flash reminding of the setting for this particular shot. I can walk over to the set, look at my note and set my camera to the proper setting.
The card actually serves two purposes, a note to keep me straight and it serves as a small flag preventing flare in my lens.
If you are interested in learning more about the world of corporate and annual report photography I have some great news. This summer, August 5-10th, 2012 I'll be teaching a workshop at the Santa Fe Photographic Workshops titled "Corporate Photography & The Annual Report". If you think you might be interested, contact the workshops at Santa Fe to secure a spot.