I take all my photos with an iPhone, now an 8 plus. (and it shows, I’m sure)
finding good, indirect daylight is the best for bringing out the dial colors in an authentic manner. Incandescent and especially fluorescent lighting both seem to really shift the look of a watch away from what my eye truly sees.
I have found that holding the camera back away from the watch a bit will allow for better focus of the subject watch itself. Then, cropping the image to the size you want gives decent results, and makes the image look like a closeup, if that’s what your aiming to do. And what Dan S says- take several pictures and pitch the bad ones.