I've never written a pattern before. Well, actually, I came up with my own version of Hermione's cable and eyelet hat, from Harry Potter and the Half-Blood Prince, from looking at the official picture from the movie. I was really proud of myself because I never thought I would be able to look at a picture of something knit and then figure out the pattern. I did this before I realized there was already a pattern out. I didn't finish writing the pattern out though because I had trouble figuring out the top part with the decreases and the cables.
As soon as I start on the hat, I will post pictures.