Lou, that 2nd pic kinda reminds me of version 1.0 of the turtle bog, when pond & bog were combined. I needed for the shoreline to slope gradually enough for the turtles to be able to get in & out of the water easily (remember, these aren't aquatic turtles). After I had the liner in, I used plastic mesh to form my faux slope [along with rocks and stuff as fillers]. Then I rented a cement mixer [no WAY I was going to do this by hand!], got some concrete coloring and went to town! Actually, I think I used Portland & sand, and mixed my own 'cause I didn't need that much gravel aggregate....
It was a lot of work, but in the end it did look nice. I could have made it thicker which would have been better for walking on, but this was just for the turts, so..... I'll see if I can dig up some pics I took.
Not sure if you'd want to go that route, but it's an option.