Just start with the the face. It's basically just a few curved lines.
STEP 2.
When your drawing the hair imagine the wind blowing to the side!
STEP 3.
The neck has a cross necklace on, but you don't need that and you also don't need the ears. But with witches having cats as familiars it gives it an added touch.
STEP 4.
This is the dress. It might take a few times to get it right, but in the end just make sure that its like the wind is blowing! Just like the hair!
STEP 5.
Add the swirls. They are the wind that is making the dress and hair move, it is the witches magic!