Being in the right place at the right time is probably the key to successful landscape photography. Patience and planning, plus an understanding of light are all that is needed.
Generally early in the morning or late in the day are the best times of day, because the sun is lower in the sky and textures and details are highlighted to reveal patterns in the landscape.
Try to avoid shooting between 10 am and 5 pm during summer as the harsh light and the high sun make the landscape look featureless and flat. During autumn and winter, the sun is lower in the sky and you can shoot all through the day.
Do not rule out bad weather because dark stormy clouds rolling across the sky can make for dramatic pictures, even more so if the sun happens to break through for a moment. Just make sure to protect your camera and yourself from the elements.
Shutter speeds will be slow because you need small apertures to keep everything in sharp focus. Using a tripod will avoid camera shake and slows you down to make you think about composition more carefully.
When using wide-angle lenses create a sense of depth by including some foreground interest. Look for a fence, a tree or a signpost to give your landscape that 3-dimensional feel and lead the viewer's eye into the picture.