I use quite a bit of stingray, but like Randy I prefer to do inlays.Now if your doing an overlay, forget the black plastic edge.Glue your skin down securely and clamp well.Now I have a varible speed belt sander that makes this very quick, but it can be done carefully with a Dremel. sand the edge down to even and then slightly round over the edge.If needed finish with handsanding down to at least 400 grit.At this point I dampen the edge and hand burnish with an antler tip(substitute as needed).I then dye the edge and burnish again then apply final sealer.For sew rayskin, I use a drillpress(I sharpen the shank of a small drill bit, reverse chuck it, and punch my holes with the press running,much cleaner than drilling.)for making my holes the sew as normal.Like I said earlier, I find inlays much more attractive (even though more work required) and about 99% of my work is inlays.I even do full inlays on my holsters.Dave
Here's a couple of examples,
Here's a sheath with stingray
And while not stingray but croc it shows a holster with a full inlay