Very nice work, but you aren't even touching the potential of HDR. HDR will perform best when you are photographing scenes that have a very wide dynamic range. The best photos (any type) are taken during the "golden" hour - the 30 minutes before and after sunrise and sunset.
The most difficult photos are at high noon when the sun is overhead. Cameras cannot capture the wide dynamic range some lighting presents, and that's where HDR can really make your photos stand out. Keep shooting, keep posting!
Bob