Okay, so you like full and proper comments. But I'm seventeen and your twenty-six so I can only say what I like about it and why cause it would be stupid of me to say what you could improve on when your so much more experienced.
Well it's in character for one thing. the way she walks when she's angry and you did that without making her anatomy look over streched or out of proportion so points for that.
You remembered the hat pins and clomper boots! Very important for a Granny pic.
The woods behind look crowded and realistic without looking messy.
but I have to say that the tatters along the hemline of her dress are is my favorite detail.
One thing I don't like is the length of her nose. I thought it was supposed to be sharp but not quite that much.
Oh, I'm absolutely delighted with this! The little sparks falling from the broom made me really smile! I find them marvelous, they make me happy, don't ask me why. It's just like I was a little girl again and finding everything that sparkles appealing. *grin* Otherwise the woman's kind of... scary. A sinister version of Minerva McGonagall.
Oooh, I love this! I'm not in the fandom and I know nothing about that, but I love this picture. It has such warm tones, and it's full of details (awww, look at that background, at the woman's face and dress!) What did you use to draw it? (*is ignorant about anyting tecnique-related*)
Technique-wise, it's nothing more complicated than copy paper, pencils, and finger smudging. The brown tone is a simple hue shift trick done digitally. I've just uploaded this to the traditional art section, since the color change is a fairly insignificant process compared to the hand-drawn part, very much like contrast fixing and suchlike.