Yes, Allan, you are so right!
There are no rules to painting, but I have found that there is a certain rhythm of things that occur in nature. To learn what to look for and to evaluate how this knowledge applies to each lighting situation, can help make sense of things.
Here is a photo I have taken of a chain. On the left I turned it into black and white so you can see the values better. On the right you can see the colors and intensity of each hue.
Links are the same size, but as they recede in space their appearance has to get smaller and less defined. This can be achieved by blurring edges and less saturated colors (greyed down your colors).
If one were to magnify a chain link, it is very similar to a donut shape, it is a round object that has dimension.Therefore each of
these links will have to have value transitions that make it appear round. In other words there will be shadow, mid-tone, highlight, reflected light, cast shadow, etc.
When links join this will happen:
1 - Shadows
One link will
cast a shadow on the other one. The thing to watch out for is how intense this cast shadow is, which in turn will depend on how the light hits that particular area of the link.
2 - Reflected Light
One link catches the light and
reflects it onto the other link.
Note how some of the reflected light is a very intense warm yellow compared to the cool whitish highlight. Pay attention to the slight value difference these two hues have when they are turned into black and white.
This won't apply as much to the chain link as it does to larger jewelery. But look how adjacent areas of skin/hair/clothing will reflect their colors into your reflective object/jewelery. Lets say you have used ochres to get the gold parts of your jewelery. If your values are correct you can pretty much introduce any other reflective color as long as it remains the same value. When painting the ring band I had a value 4 or 3 dark ochre and it looked rather dull. When I added the same value Venetian Red (skin color reflected onto the ring) the whole thing just came to life.
Remember that reflective objects can have several reflections vs. non-reflective objects which have a light and dark side.
3 - Highlights
Depending on painting technique, highlights seem to be added differently.
I tend to work with my lightest color mixed with white (value 9) and only
add the pure white (value 10) at the very end, sort of as the cherry on the top. Some say highlights should be crisp and sharp, others blend them in. Then there are those artist who use thick paint to make the elevated paint catch the light.
I think the reader could benefit from more input by others on this subject.
-Lost and Found Edges
Ok, so what does that mean. When an edge is lost it means that the value of lets say the particular area of that link is the same value as its background. See where I marked "Value" , by squinting and looking at the blk/wht that area ideally needs to disappear into the background. There are no sharp edges either and therefore it gives the illusion as if that part of that particular link seems to recede in space.
Now lets look at the opposite case. Anywhere you can see a link coming forward, there is a difference in value between adjoining areas. If you really want to emphasize it coming forward add a sharp/thin line.
-Cast shadows
The links/chain will cast a shadow, so observe how intense this shadow is and how it moves across the planes.
Of course most chains are tiny in comparison to this sample, but now you know what to look out for. Of course I always say this is all so much easier said than done

, but that's the charm of painting. There is always a new challenge!
For now this are all the pointers I can think of. Please feel free to add to these observations and give visual samples, so we can learn from each other.