So, the first thing I did was determine if I wanted the argyle diamonds to be horizontal or vertical:
I decided that the vertical looked better, having the diamond's long points be up and down. Then I had to decide if I wanted it to have two full gold diamonds, or two full black diamonds.
I decided to go with the black.
I cut out two strips (the fabric was 60 inches wide).
Then I lined up where the diamonds met, and trimmed both edges. Using clear quilting thread, I sewed the two edges together.
The seam is hardly noticeable!
Now, for the hat, I traced the pattern, again with the diamonds going vertically.
You cut a front and a back piece, then sew up the sides, right side to right side (see a more detailed tutorial on that here). I left about an inch or an inch and half undone at the bottom, because I wanted to sew that seam on the outside, and fold up the brim.
Turn it ninety degrees, and sew up the little V that's still open.
This is the outside of the brim, with the seam on the inside. (Does that make sense?)
And the final product:
It turned out so cute! She really loved it when I gave it to her!
(This is me, trying it on. I only wish they had the blue and bronze of Ravenclaw, and I'd made myself a set!)