Operation clean up!
Make sure you tidy as you go when shooting landscapes. At many of the popular sites I went to, I was met with this unsightly mess: litter that people had left after visiting. At best it blows around and ends up in your frame, meaning you either have to go and pick it up, or clone it out on the computer later; at worst it pollutes the environment and has a negative impact on the habitat and wildlife. Best practice is to leave the site as clean as when you arrived, or better still cleaner.