Once the robe is done, you've got the foundation for a ladies' Bible costume, but without the extras it really doesn't look quite all there. We use two 1.5 yard head drapes...45" fabric is best, but 60 can work...if it's too heavy or cumbersome, just trim it down to 45"-54" wide. These work best if they are complimentary to the robe...not matching. A simple serged edge in matching or blending thread is sufficient to finish the edges of those for the stage.
A waist sash isn't really necessary, but it does make the costume a little more flexible; a costume that is a little too long can be tied at the waist and then bloused a bit above the tie to pull the hem up enough so that the character is not in danger of tripping. I have used both 7 1/2" and 8 1/2" strips...they yield a 3" and a 4" sash, respectively. Which you use is your preference. For simplicity, I cut two strips from the remnants (if there are any) of the robe fabric; we really don't want the sash to be a focal point; it's a fitting tool. Usually I will trim one piece down, then seam the two pieces along the short end, right sides together, to make one long piece 72" - 90" long (depends on the, um, girth of the person ;) ). Note: if you use the cut end as one of the ends in that seam, it will leave selvedges for the ends of the ties and...no seam finish necessary ;). Anyway, seam the long edges, right sides together, with a 1/4" seam allowance and turn the tube right side out. Sash done.
The head band...the thing we use on top of the drapes...is a little more involved. I cut 3 strips that are 3 1/2" wide. Which fabrics I use just sort of depends on what's left and how much body it's got...the head band needs something that is just a little stiffish (something drapey, like rayon crepe, just collapses and doesn't work well). Sometimes I will even underline a drapey fabric with a stiffer one to get the body needed. So...that's a per-case judgement...three strips of the robe fabric, one strip of each of the three fabrics...or a mixture of the robe and drape fabrics or, sometimes, I'll pull a fourth coordinating fabric from the remnant pile to make the headband. It just depends on what works. Fortunately, the fabric I used for the grey robe was workable, so I used it for the headband for this costume.
Anyway, take the three strips, sew them into three tubes,wrong sides together with a 1/4" seam allowance, and turn the tubes right side out. Then take one end of each tube and stack them slightly offset from each other and zig-zag them together.
Flip the strip on the bottom of the stack around to the top side to cover the seam, then begin braiding the three strips...be careful not to pull them too tight.
When you have a braid long enough to wrap around your head and a thumb with about 1" overlap, zig-zag the braid and trim off the excess strips (save one of those strips...you'll need it later)
(the rest of this is hand stitching...I know, bummer, but this is the only hand sewing on the whole costume). Wrap the band around the head, with a thumb underneath (it will be going on over the drapes), and hand sew both the outside and inside edges to the band. This stitching doesn't have to be neat...it's going to be covered...but it should be secure.
Then take the reserved end and stitch it to the inside of the band at the overlap. Wrap it around the band a couple of times, covering the stitched-down ends of the band. Finish with the wrap on the inside of the band, tuck the end of the wrap inside that tube and hand stitch it down.
Warning... Once we started doing these, no one was content with a simple tied headband... ;)
If you're wondering what to do with the wraps, I've got a little Head drape how-to on how to actually put these things on...there's a photo set for the squarish drapes, and one for a long oblong drape ;).