(interestingly i used to call her that too (because of your art no less) feel free to continue with the name though i should warn you though, that it is simuler to the ponys "Sandy Sole" and "Sandstorm" while Mj[ouch]lna (i should learn that accented letter it is in my own name) is i must admite very unique and now i can not help invissioning her and Quick Fix as nords. (helped by the fact that there manes are simuler to the regions predominent hair coulers)).
I tried to change her mane and tail style a bit, so for her tail i just did a simple styled one, but then made little outcroppings on it, and they have a little blue ribbon in it, even though it doesn't look like a ribbon ^^
All I did for that was create a new layer above the body's colouring. I turned the transparancy to 10-20% and then made white shapes over the body. It is mind-numbingly simple but yes, that's how I go the crystal-esque appearance. I did try it with many layers and loaaaads of shapes overlapping but it just didn't do more to the picture for the effort it was worth, so I stuck to just a few. Triangles, quadrilaterals and pentagons are good.
Sparkle wise, I just made one sparkle and replicated it over and over, adding a few big sparkles, more smaller sparkles and loads of little baby sparkles.