It's a great way to make use of old clothing that would otherwise end up in the landfill. I like to find unusual pockets, trims, labels, waistbands and even fly fronts to add to these quilts.
Every quilt is completely different.
Then I sew the strips into strips the length of the quilt. I used to plan these out carefully before starting to sew, but I find I save time and the result is about the same to just sew the pieces randomly. I layer the completed top with poly batting, often using strips of batting left over from other quilt projects, and backing. A yard and a half of backing fabric is enough. Sometimes when I find a nice piece of decorator fabric for backing I make a wider quilt.