Light and Shadow
Typical camera flashbulbs that light from head-on tend to wash out your subject and flatten the image. Back-lighting in accordance with key lighting schemes or directing your flash toward a side wall or reflection board will enhance the subject's features through the use of shadow and contrast. Adding some fill light to create layered texture will also enhance the dimension of the image. Take advantage of the sunlight on outdoor shoots. The sun is sometimes a powerful back-lighting tool at certain times of day but be careful not to let it overpower the image. Softboxes or reflection boards are also valuable ways to manipulate outdoor light and should be used to help soften shadows, especially when facial features can be harshly exaggerated under stark lighting conditions.
Lenses
Wide-angle lenses are an effective way to add depth to a photograph because they are designed to capture greater amounts of visual information through their angle of view. This causes more exaggeration to items in the foreground so as to contain background subjects with more clarity. So when you use a wide-angle lens you are utililizing the foreground of your shots to draw the eye in at first, then affording the viewer a deeper guidance into the composition of the photograph. Telephoto lenses, on the other hand, condense the angle of view and can make longer distances between objects seem compressed. But this too will help create dimension as long as you know where to place your camera.
Position of Camera and Subject
Where you place your camera in relation to your subject is an effective way to create deeper perspective in your photographs. The placement of objects to one another will have a layering effect on your work, so items that are small in real life look much larger in comparison to other objects in the composition. Setting your camera up close to your subject enhances the foreground of the image while keeping the background in focus to a greater distance and through this technique you are capturing more visual information. You are giving the viewer more to look at and bringing them into the photograph by doing it. The complexity of your composition allows for further exploration of the scene even if your photograph is very simplistic. The lines and perspective are doing the work because you arranged them in a way to keep the viewer engaged with information through proportions.
Color
Color is one of the simplest and most obvious ways to attract attention through not only contrast, but through saturation. Contrast offers a heightened stimulus to the eye because there is a basic comparison of images that allows the viewer to distinguish between them in proportion and position to one another. The saturation process for color allows the photographer to alter the depth of the hue. Deep purples and blues have greater severity while muted hues have a softer approach. Dramatic colors are used to invoke strong initial reactions to a photograph to grab the viewer immediately, and contrast will engage them in a deeper view of your composition.