If you are shooting against a white or black background, you can give the illusion of having shot something in a huge studio. It is really quick and simple using Photoshop. Just make sure your background is either pure white (use the dodge tool) or pure black (use the left hand slider in Levels or the burn tool).
In Photoshop, press D on your keyboard to give you the default background colors (black and white). The X key will toggle which is the background and which is the foreground.
- Set your background color the match your photo.
- Select the crop tool and drag it across the full size of your photo.
- Grab the edges of your crop frame and drag them out to the size you want.
- Hit Enter on your keyboard and the background color will be filled in.
The photo above was taken against a 6' x 7' Lastolite Hilight background with white vinyl on the floor in a small living room.