I'd suggest a few improvements to get the most out the design you have.
They are likely ones you yourself have considered.
The fore ground very front of the tank, that gravel layer is not even.
You can take a paint scraper/Kent algae scraper etc, and push/pull that gravel away from the front of the tank down to near the bottom of the tank and tuck the grass etc into that space and give a higher more gradual feel going from front to back in the grass, in effect, giving you a greater sense of depth.
This will straighten up that line, who wants to see gravel in the front view of their tank anyway?
I think that plant behind the mound is poorly trimmed, you know it also.
Perhaps a different plant, maybe Rotala green, Mic umbrosum, and nice leafy green plant and keep it trimmed right above the mound, like a sunset effect.
I realize that in general, the tank will not look that way much(R green is pretty good there though), but for a photo at least, consider that, or a red plant like L acurata etc.
The right corner needs tidied up some. Your choice on what you want to do there, but it needs some trimming or sense of order there.
Do several water changes the week prior to the photo shoot.
Do a very large water change that morning and take a photo always at night, right before the lights go off ands before the plants close up.
Clean tank well all week etc, glass etc, fluff the plants often.
Take several photos with different speeds/F stops etc/ISO's.
Then use PS, some image software to clean up and sharpen the haze out and bring out the colors you like to present.
I can clean up a pic if you post it etc to give an example.
Regards,
Tom Barr