So this took a long time. Mostly because I still don't know what I'm doing. And I kept changing my mind.
Luna, post Nightmare Moon, restored to her glory and taking a stroll.
I admit I can't explain why a pony would be wearing ermine. Perhaps in Equestria, they grow on ermine trees? But I really couldn't leave it out after discovering that in Canadian heraldry, the ermine pattern indicates a second-born daughter.
And yeah, the lily is not an accurate lily, because lily plants have buds at the top and blooms lower down, but oh well.
Done in ArtRage, with chalk, some glitter, and a little bit of airbrushing.
This is really beautiful! My only criticism would be that the top of her hair kind of sticks to her head, I think it would look better if it was poofier. Other than that I think you did a great job.