HOW ABOUT......another 2 clay pots upside down and a long piece of slate or similar type rock or log to make a bridge type basking area...then you can add some water lilies to circle around one side..
On the search bar of amazon.com search floating pond island. They are great looking and gives you a place to plant things and your turtle a basking spot. Check them out.
I tried the clay pots. They stick up too high on the pond shelf and it's too low at the bottom of the pond. I did add another boulder and now have two basking at one time. I'm going to get a couple more boulders for the other shelves. I may eventually try the ramp idea. It seems they get on the boulders easy as they have a slight tilt and angles for them to grip.
I am assuming we are talking about your pond turtles? I would avoid styrofoam myself, they might want to try and eat it, then you got a whole other host of problems. Different size bricks and flat rocks should work the best, depending on the size of your pond/enclosure. I use those 8 by 8 by 16 cinder blocks and go from there.
The tank does look a little too bare, and the author's using a coiled UVB bulb which is bad. However the above tank basking platform is cheap and the materials are easily obtainable.