I have an appeal to make: please do not over-do your HDR images. I feel like this technique is positively abused. Its original intention was only to better approximate the human eye's dynamic range, now you see all sorts of gaudy images that would make Thomas Kincaid, King of Kitsch blush. Please use it responsibly.
Also, if you have a tripod the best way to shoot landscapes are:
1. Always shoot ISO 100 (with some exceptions -- sometimes ISO 200 on some cameras actually had greater dynamic range) so you have the least film gain/noise and greatest dynamic range of light to dark tones.
2. If you have or the scene allows for a gradient neutral density filter, go for it. It underexposes the sky and allows the ground to be properly exposed for a more dramatic look without blowing out the sky or underexposing the ground. This doesn't work if you have mountains or something popping above the horizon line.
3. never let the horizon split the frame in half. It should always be higher or lower than the midway line of the image.
4. Set the camera to manual exposure if you can. The landscape scene mode on some cameras will substitute for the next series of steps if you do not have manual controls...
5. Stop down your aperture to maximize depth of field.
6. Get as wide as possible with the zoom.
7. Find the hyperfocal distance for the scene, or set your focus to infinity if you don't have any foreground objects (though it helps the composition tremendously). The hyperfocal distance is where everything beyond that plane is in focus. More here
8. check your white balance. You probably can't set this manually in the field, but warmer is generally better unless it's *too* warm of course!
9. Meter your scene avoiding highlight and lowlight clipping, I often spot-meter for this, but good ESP metering might handle this adequately (I just don't trust them as much). If you have a histogram display, keep the exposure to the right without blowing highlights (meaning they don't stack up on the right edge of the histogram). This helps keep noise out of shadows. Try using a separate AEL lock/toggle once you have the exposure you like.
10. Go with a bulb exposure if possible -- meaning ideally you use a remote to trigger the shutter to avoid shaking. If you don't have a remote, use the 2 second or 10 timer and possibly use mirror lock if you have a DSLR. You need to void shaking the camera, even with the shutter for long exposures.
11. bracket all of your photos. Try different lengths of shutter exposure both over and under what you think are the right settings. This helps to superimpose images later for HDR work (better than highlight and lowlight recovery if you can frame the image consistently without moving the camera), and if you're wrong you'll probably get the right exposure in there somewhere.
12. Shoot BEFORE the actual sunrise and AFTER the actual sunset. Colors are more brilliant at these times. The difference between a few seconds at these times makes a noticable difference in your images too. You generally never shoot at mid-day (with exceptions of course).
13. Please also don't over-saturate the images afterwards. You lose detail, depth and any sense that it really might have looked like that and you actually saw it that way.
OK, that kind of mixed composition and technique together. In terms of simply getting the correct exposure, check your white balance, watch our for blown out detail, get everything in focus and don't shake the camera.