I had a go with the dog photo. In all the versions, I cropped out the shadow at the bottom and tried to lift the shadows as much as I could. Still, the problem is that you have a very dark subject with a very bright background. You exposed well considering the issues, but I finally got tired of trying to keep the background in and just erased it for the last version.
The biggest difference between your photos and devisor's, by the way, is that he has completely controlled his lighting (something that I can't do either). It looks like you had very mid-day, flat lighting, which is why your photos don't naturally "pop" as much as his. One of the things that you can do to fix this is shoot either earlier or later in the day or make sure you that you control the lighting that you do have (i.e. know how to use backlighting, when to overexpose the background, etc).
My post-processing taste is quite a bit different from devisor's, but maybe you'll like something here. If so, let me know which ones, and I'll tell you the steps.