WIP
might just do reference planes and use them for drawing.
might make a 3D CG dummy version to cheat like a bastid when drawing.
might make a 3DStudioMax model, rig it, and just render instead of drawing.
the legs might end up more like those in the cartoon.
or maybe not.
dunno.
just thinking at the moment.

anyway, the proportions are accurate to horses and hackney ponies, except for the deviations noted in text.
the scale is my own, based on apples of all things.
I know that a lot of people prefer to think of the smaller adult ponies as being roughly the size of dogs, but I don't buy it.
I tend to think of Celestia as about the size of a tall Arab, and small ponies like Derpy and Octavia as being about the size of a small Hackney pony. I've arranged the "mane 6" and some other characters along the continuum between those two points in a grade I think makes sense.

comments, questions, criticism, even argument (provided it isn't simple partisanship) are all welcome.