I agree with you totally. It seems like every aquascape I see is elevated on the sides with a trench/ravine in the middle. That has to be the way to do it. Any ideas of what I should do with the big piece of slate? I appreciate the advice.
First I'd like to say this... There is no right or wrong in this IMO, its art and art is left to interpretation. You do what you want and what makes you happy
its your tank, you need to view it,no one else.
With that said, I think the slate could still be used(maybe), if you build say the right side up with rocks making caves you could angle the slate down to kinda hide some of the caves. Or just remove it totally.
I think and again just my opinion. It would look nice if you built it up with the same rocks you have on the bottom. Stacking them unevenly then maybe a piece of driftwood reaching to the top to give the tank height.
You could also, do a complete rock scape with no driftwood... It's really up to you. A good thing to remember is, when scaping, take a break and a step back. View the tank with fresh eyes and see where you stand. Something my hit you. Something may be needed to add or taken away.
Aqua scaping is never done IMHO, its always a work in progress. I've rescaped my tanks many many times.
It's when I can't find anything to take away that I now I'm done.
It you notice "most" of scapes have included adding then weeks later new scape where I removed the object or objects I placed in the tank the first go around. The latest scape I just added some basic substrate rock work.
That's pretty much it. Here to help of you need it.
Again always remember the most important thing!! If YOU like it then that's all that matters!