For the overlook shot, I stood at the edge of the parking lot. I used the hills at the bottom right for reference. Matching this shot was pretty easy because I printed out a picture of the shot and brought it along with me. For the scene with the Sandcrawler, there are multiple places that the scene could have been shot because the hills are so far off in the distance. I’m sure if you walked around enough you would be able to find the exact hill they walked up. Another possibility is that they may have placed the camera on the ground to make the hill appear larger. For my picture, I just put my model on top of the hill behind the viewing area for the R2-D2 canyon. I was losing the lighting conditions and people were leaving, so I just rushed to take the picture. For the shot in the movie, I think they had the camera further off to the right judging off of the mountains in the distance. You definitely were able to capture the scene better than I was able to!
Here is the hill I walked up to take my picture of the Sandcrawler:
http://imgur.com/a/CJ2n6
I think that you were closer to the actual location because the hills have rougher terrain compared to mine. Also keep in mind that it has been around 40 years (wow that surprised me) since the scene was shot so the landscape may have changed a bit.