How to Photograph Vintage Watches?

Good light.

That’s 90% of it.
Try and position near a window for natural light

Practice.

I use a tripod and a Canon macro lens with a remote shutter button for image stability. I've experimented with light boxes and the such like but now only ever use natural light, I mainly shoot next to a window which has both a vertical blinds and a very light linen/lace type curtain. I also generally use a plain black background for style continuity.

That's pretty much it. Not super pro by any stretch of the imagination, I don't even know to do image stacking for instance, but a very simple set up that gives me what I find to be pretty pleasing results. Buying the macro was game changing, before that I was never satisfied no matter what I did.