Here’s a 7-minute video by photographer Dustin Dolby of workphlo that demonstrates how to photograph luxury watches in a studio setting with entry-level lighting equipment.
The focus here is getting a super sharp shot that would “look good in an Instagram feed.” A black background helps to isolate the watch, creating a canvas to use to paint it with light and achieve a glistening face.
Using a reflector helps to “milk the light” you’re using, filling in the shadows on the opposing and originally unlit side of the watch. The aim is to make sure all edges of the watch are properly illuminated, giving a hard contrast between the subject and the background.
A diffusion disk allows you to create a nice fill light for the watch face, using it as a portable softbox so you can fine-tune the position.
To achieve the ultimate glistening shot, hold a flash close to the watch, at an angle, to make to sparkle.
Finally, mask out the background in post production to create a pure black backdrop.