Once you're comfortable with the technical aspects of exposure and the various components of composition, you need to become familiar with the different aspects of lighting.
Light holds the key to the next level of creativity and personal expression.
The majority of travel pictures are taken with the natural light of the sun, but you'll also use incandescent lighting indoors or at night and flash when the available light is too tow. There's light and there's the 'right light'. The key elements to the 'right light' are its color, quality, and direction. Once you understand these elements and the way they interrelate you can predict the effect they may have on a subject. This will help you decide what time of day to visit a place.