Hi Ned, welcome aboard.
I agree with everything said above, the only extra advice I would give you would be keep the ultra thin border, but go for black instead of white, white sort of bleeds out the edges of the shot slightly (for me at least), but that is my preference I suppose and so it might not be yours and of course that is just fine. Also I think these shots may be handheld, as there seems to be the tiniest bit of softness in certain areas of the images, so if I am right and they are handheld, then I would advise the purchase and use of a good tripod for all your work - yes I know, they are cumbersome and annoying to carry around and also you can feel a bit of prat when you first start using one in public, but for all your work and especially for lowlight shots like these, if you want to get that ultra sharp clarity of detail throughout the shot, then you simply cannot beat using a good solid tripod. In fact I would go as far as to say that using a good tripod, is the single easiest way to massively improve your photography in one easy step.
If they were taken using a tripod and it is just my screen or the jpg compression that has introduced a little softness, then please accept my apologies and totally ignore the above.