After feedback from Phil, i changed the background of my image to a more striking sunset. This allowed me to add orange highlights to the pillars to make them stand out more. I also added highlights behind the pillars but i couldn't get them to stand out as much as i wanted as i was working on black. I tried to layer some grey on first, then go over that with an overlay of dark orange and blend it back into the black with low opacity brush. I also darkened down the grass in the background to make the steps stand out more.
I am very pleased with the way this piece has turned out.