I lined the hat with my practice fleece hat, but didn't take any photos of that because it was very simple. If you'd like more info on that portion, just email me or leave a comment and I'll get back to you.
I started the ears by putting the hat on J and measuring the size for the ears I wanted. I decided on 6.5" x 4" for those classic, generic, hang-down dog ears (and allowing for 1/4" seam allowance all around). I cut a piece of scrap paper to size, folded it in half lengthwise for symmetry, and cut in a rough dog ear shape. I used my pattern to cut out four ear pieces.
I alternated the ear pattern in an attempt to save fabric, but I don't think I saved all that much.
The rest was very simple. Pin two ear pieces, right sides together, stitch around the edges but leave a one inch gap for turning the ear right side out. Hand sew the gap. Baste ears to hat in appropriate location. (I basted the ears because I want to be able to remove them easily after Halloween.)
The second zig zag seam around the perimeter is from the new lining.
Ta-da! I like how it turned out. Next up--the tail.