Never used a single damned one of any of those. Never needed to and never will. Signatures are all right if you actually need one (i.e. are worried about art theft), placed way off to the side and very small and unobtrusive, but it's like a book- you don't see an author's name in boldface in the center of every page.
A plain white edge to a photo or one of those messy enlarger-created edges makes the picture look more arty to slack-jawed rednecks and your grandmother, but really isn't at all necessary unless you're trying to sell, at which case there'll be a matte and frame anyway.
Textual commentary or visible titling on the piece itself is every bit as awful as applying a random Photoshop filter to the piece. It's what whiny pretentious DeviantArt-posting teenagers whose mothers told them they're geniuses do. Every time I see a big funny-texted title in white on a photo (or, Christ help us, poetry), I'm not just discouraged from buying the piece or taking any further interest in the 'artist', I'm suddenly compelled to murder them with a book on design. And I'm far from the only one, though I might have more violent intentions than most others who know **** about photography or art in general. The point is the ****ing picture, not some silly pretentious interpretation of what the picture means- if it isn't a strong enough photo to carry a message or emotion itself or can't be interpreted by the viewer, it belongs in your trash can, plain and simple.
The rules naturally change for photos that aren't intended as standalone art pieces (as part of a larger webpage design, for example, borders, textual notations, even random Photoshop filters can be just fine in cases), but less is definitely more for photography itself. You want the picture to speak for itself, if you drown it out with doohickeys and whatchamajigs and snippets of your favorite Nine Inch Nails song (eugh) that won't happen.