Recently in Diamond, I traded my Feebas with my friend's Houndour. Since I was nice enough to give her a Dusk Stone in the trade, she decided to be nice too and trade me a Razor Fang. That worked out for me--I was finally able to evolve my Gligar!
(I had plenty of extra Feebases and Dusk Stones on hand, so I didn't lose much.)
I then started training some of my Dark-type Pokemon, and my Seviper, in Route 214. While doing that, I encountered a shiny Geodude! Fearing it would use Selfdestruct at some point, I threw a Quick Ball at it, and to my relief, it worked. Hooray for my third shiny! (The other two are Clefairy and Gastly.)