Help adding to aquascape

[Heres_doe_]

My scape is right in the middle. I want more space towards the back glass. I have a few pieces of flat rock. I want to put a higher scape behind the scape I currently have but I don’t want to use all rock. Anyone have ideas with pvc and rock or just pvc? Show me what you’ve got.

 

[Heres_doe_]

I tried posting from the app and it kept posting not sure why. Also didn’t post the pictures.