Firstly like any place of worship sensitivity and obeying all rules are necessary. This can be frustrating as many images you would like to explore are out of bounds. Primarily they can fall under a personal code of ethics, such as photographing prayer. Towards the rear of the Mosque where women are permitted to pray, some incredible photographs could have been captured - a woman's face almost in tears as she went through her obligatory Sujud prostrations.
The time that I arrived on both occasions was around 7 o'clock, I really wanted to capture the Mosque in 'colour' during my visit the skies were very grey, and no chance of blue skies. So I made sure that I took some photographs at night knowing the building would be illuminated. This is well illustrated in the very first image taken at 19:14 and only 30 mins later the last image at 19:45.
Also consideration to mixed light sources and colour balance needs to be accounted for. It would seem you either embrace the mixed casts or try to correct through post production. I have left it on most of these as I prefer the feel that it gives. Although perhaps not as you would have seen it, the results are still pleasing.
Converging verticals: also play a part - more so with wide angle usage. I think in the future I might use a wider view to start with, then allow for post production of correcting these. A larger canvas is required to pull and stretch the image out, then crop to a 'standard photo format'.
Also the use of a tripod. I had one back at the hotel, but as this was taken during my 12 hour shoot it was left behind. Instead these were shot 'hand-held' using a higher ISO typically around 1/30-1/60 at f2.8 exposure. This all effects the quality for reproduction at a higher print size. In retrospect covering this subject should have been one days shooting, taking time and exploring more angles.