What I used:
- invisible thread (any thread in matching colors would work fine too)
- poly fill (I have tons left over from when I made a bunch of play food a few years ago)
- plastic lid (mine is from Costco milk)
Cut two felt circles--one the size of the lid, one a little bigger.
Sew the sides of your rectangle together, then sew on the smaller circle.
Stuff your lid down into the cushion.
Put some poly fill in.
Sew the larger circle around the top, leaving a hole to stuff in more poly fill. Stuff and stitch the hole closed.
To decorate it, I cut one zigzag out of felt long enough to wrap around the cushion. I just "free-cut" it. Then I stitched it around the cushion.
Then I cut a circle into a spiral shape and rolled it into a flower.
I liked how it looked from the other side, so I turned it upside down and stitched it to the zigzag. And there ya go!