I'm not professing any expertise but I did have a play a while back.
I did a ring making day and took some pictures during the course and some attempts at product shots afterwards at home.
https://www.flickr.com/photos/amcuk/albums/72157682765758465/with/33461980734/
For the "product shots" I used a standard kit lens and some FOTGA extension tubes.
The tubes were cheap from eBay and maintain the electrical connections so focus and aperture were controllable.
I set the camera on a tripod and used daylight, a desklamp, iPhone and small maglite torch (yes, white balance is a nightmare).
I fixed the ISO as low as possible and used aperture priority to attempt to get the deepest depth of focus with what I had available.
The slow shutter wasn't a problem as I was using a 2 second self timer and the tripod and nothing is moving.
Using live view and fixed lights you can see what you're doing. I doubt I could have done much with on camera flash.
I was amazed at the differences from using different backgrounds made in bringing out the texture of the rings.
The difference minor changes in moving small lights to create highlights was also surprising.
I was also amazed (afterwards) that my attempts at cleaning the rings and the backgrounds were as feeble as they were. The smallest fingerprint, eyelash etc.spoiled a shot and I thought I was being careful!
If you have the time I'm sure you can get decent results, if you don't then I might consider asking for some professional 1 to 1 teaching.