Well, shinies give me an inspiration to draw them. And how I get shinies is through RNG. I like to RNG some of my favorite shiny Poke'mon (like Deino) and go from there. They can all have multiple sets, so when I battle my friends, they may not know which set I'm using. More of an example is different natures. I have RNG'd three different Deinos; Naive, Timid, and Jolly. No two of my shinies should be alike. There has to be at least one difference.
Like Christian said, I like using [shiny] Poke'mon to their full power, regardless of what my friends say. I usually can find inspiration by looking at different battle sets as well. If I find one that's interesting/popular, I can RNG a shiny one (if I already don't have it).
In a nutshell, I love shiny Poke'mon. And that's why I like to RNG. :>