_{^{Video: by Robert Grant. Article: by Sasha Gitin}}

Learn From Observing:

4 Steps for Lighting to Show Texture (outdoors scenario):

1. Look at your subject to analyze what kind of texture it has.
2. Observe the direction of light that is falling on your subject. The light should skim along the top creating highlights on the edges and shadows in reliefs.  
3. Position the camera: The shadows should be directed towards the camera (angle may wary)
4. Position of the light source:  Sun moves around throughout the day. Not only it moves around (east to west) but also up and down (dawn to dusk).   Analyze what time of the day the sun will project the light on your subject at the desired angle. As a rule of thumb the lighting for texture is best early in the morning and late in the afternoon.  Note: Hard light (direct sun) will create darker shadows while diffused light (cloudy overcast) will create softer shadows.

3 Steps for Lighting to Show Texture (studio scenario):

1. Look at your subject to analyze what kind of texture it has.
2. Light against the grain.  Position the light source at the angle so that the light skims across the textured surface.  Make sure the shadows are falling towards the camera and not away.
3. Push the button. (well it a bit more complicated than that but the video above explains the details)