Agree with the others, 90% of landscape photography happens before you push the button.
FWLIW, I'd rate the priorities as:
1. Light (weather and atmosphere, sun angle, possible presence of reflected light, etc.)
2. Subject. Gotta find something pretty!
3. Composition, exposure, DOF requirements. All must interact to meet whatever 'vision' you have for the scene.
4. Camera. 'Sufficient' megapickles and lens resolution.
5. Post processing. Set black and white points, crop here and there, clone out the bug on the sensor, etc. If the image doesn't look promising at this point, go back to step 3. If it's looking good, go ahead and dodge/burn/tweak to fine tune the picture.
If shooting a different type of subject such as people in a glamor/portraiture/wedding context, these priorities might be completely re-arranged. (Not that those three are all that similar.)