1) cut four 18" squares of fabric
2) sew a line/border about 1/2 an inch in from the outside of the edge, all the way around
3) pull out threads on the edges, this takes a while, but is so pretty it's worth it
Of course it will be a softer fuzzy edge when washed. Project takes about an hour, most of which is pulling out threads, which is soothing and satisfying.