Since everyone's so generous sharing their WIPs and despite the fact that I am not at the level of most posters here - some astounding renders so far - here goes the next iteration - just a crop - after much exhaustive masking, population placement and object scaling. It really is a challenge to create close-up scenes that look realistic as has been noted elsewhere.
I may return to the details here (so please feel free to make suggestions), but I am on to the more distant parts now, otherwise I will never get it done.
The hardest thing seems to be that you have to render it out in high quality to have a good look. What may come out ok with .65 detail setting and AA of 3 looks totally off (especially color mix-wise) with .85 detail and AA6 (makes sense of course). So quick low quality crop renders only go so far. Already takes about 70 minutes for a decent resolution and quality render, this will only go up now....