The key to getting the sharper landscape and nature images is to use specific digital photography techniques. Disciplined use of these techniques by photographers leads to technically better photos.

Use a sturdy tripod – Camera movement is a common culprit of soft photos. Using a sturdy tripod will usually alleviate the problem, and also allow you to compose your image with precision. The use of a tripod allows the digital photographer to use a slower shutter speed, for a greater depth of field due to the corresponding aperture.
Use an appropriate ISO digital camera setting – Selecting the proper ISO setting on your digital camera is also one of the keys to sharper images. A low ISO setting on your digital camera will produce finer grained images, but requires longer shutter speeds and/or a large aperture. A higher ISO on the other hand allows the photographer to utilize a faster shutter speed which can be good for capturing sharp pictures of moving objects, although it sacrifices image noise.
Use a fast Shutter Speed – To freeze moving objects such as aspen leaves quaking in the wind or a tumbling waterfall, use the fastest possible shutter speed. Keep in mind however that your depth of field focus will be reduced at faster shutter speeds due to the larger aperture.
Use a Small Lens Aperture – By stopping down the camera lens, the image appears sharper by expanding overall depth of field focus. This results in objects both near and far being in good focus.
Control Subject movement – Much the same as camera movement, subject movement can be damaging to image sharpness, however sometimes subject movement can be impossible to control. For instance shooting close-up pictures of wildflowers on a windy day can be quite the challenge. The best advice is to restrategize, and go with the flow. Forget the close-up pictures, zoom out, wait for a lull in the breeze and shoot the pretty landscape.
The trick to getting better photos is to find that ideal combination of variables. Always use the lowest possible ISO setting, and for the best depth of field focus select a smaller aperture. For still landscape pictures, use a tripod and slower shutter speed. For moving landscapes, use a faster shutter speed to freeze the motion.