HDR Photography Tips: Become a Cloud Watcher
High dynamic range photography happens outside a good portion of the time, which is (conveniently) where clouds tend to congregate. So for better HDR photographs, pay attention to the clouds: how they move and in what direction.
Also pay attention to their position in the sky in relation to the sun and what time it is. In early evening (the golden hour), the sky can look completely boring one minute and light up in a fantastic display the next. The sun strikes them from the side, and then underneath as it sets.
In the morning, play this scene in reverse — the horizon will glow, then the sun will peek up and light the bottoms of clouds, then the sides, then the tops.
This figure illustrates several cloud formations at different times during the day and in different conditions. You can see there is a lot of variety. When you start paying attention to clouds you will start seeing more and more detail. When you start seeing this, you will start shooting better clouds (and skies, and scenes) more on purpose. Then your HDR photos will get better.