I'd echo slobodan's comment on the sky. I have a thing about weird unnaturally coloured skies, I recognise the orange as traditional in UK urban areas, but can't help thinking a deep inky blue would be a better [more realistic] top third. Don't get me wrong, it's something I continue to make an arse of in my own photos, but I am conscious of it and try to resist the temptation to make it colourful just to add interest.
So, if we're trying to add interest, [there's plenty in the middle ground ] maybe a flash or other light source [torch?] to provide a touch more detail to the Calton Hill foreground thingy, rather than taking the more silhouetted approach. [Take this with a pinch of salt, I'm viewing this on a crappy laptop screen.] This leaves the upper sky to act as a backdrop to a glorious cityscape.
Hope this doesn't seem to harsh, feel free to get your own back on my Loch Achray shot.