The other simple waistband is a band.  This method needs a zipper at the band opening, so don't use it if you don't want to sew in a zipper.  I use a stable polyester tie and stabilize it further with interfacing to prevent stretching.  For a 1 1/4" wide band, cut a strip from the tie that is 3 1/4" wide and about 3" longer than your waist; fold in half lengthwise.  Mark the length of your waist on the tie from 3/8" from one end.  The extra length goes on the back left side.  Sew one side to the right side of the skirt, press the seam toward the band, then sew the ends and fold the band over the seam.  Stitch in the ditch on the right side.  Add hook and eye or button & hole.