How you go about it depends entirely on the scale. IMO, mail should be only a texture in 90mm and smaller. Almost every figure made today depicts the mail rings way out of scale. I guess modelers want to see indivudual rings even though it isn't possible in most scales. Some of the best scale mail work I've seen in 54mm are LaTorre's Northumberland warrior and Blank's Alexander Nevesky. In both cases the sculptors downplayed the rings, especially LaTorre. The result is far more realistic than when actual rings are attempted.
In large scale, 120mm, it might still be best to go for a texture rather than actual rings. Frankly, I haven't created mail that I've been happy with in the larger scales. 70mm and smaller are much easier to create a realistic appearance. An important consideration is the firmness of the putty. It needs to be fairly firm, otherwise your texture will be too deep. Soft putty means soft detail also. This all requires you to work small areas, don't tackle too much at one time since your window is narrow before the putty sets up too much.
In busts, forget it. Unless you're ready to go Augie's route, there is no convincing method. Again, that's just my opinion.
HTHs