Rouleau ties and loops as well as narrow buttonholes are all suitable closures for sheer fabrics.
To make narrow rouleau ties, cut 1" strips on the bias. Fold the strips in half, right sides together and pin. Hand baste the edges together.
Machine stitch using a 1/4" seam allowance. Stitching should be a scant 1/8" away from the folded edge.
If you have difficulty stitching a narrow 1/8" try stitching over tissue paper, which will help to stabilize the fabric.
Use a tube turner to pull the tube right side out. I pin the ends of the rouleau to my ironing board and steam lightly to take out the curl. Rouleaux can be used to make ties as well as loops for a button closure.
The rouleaux ties and neckline on my blouse were all cut as one piece of bias fabric. I sewed the rouleaux ties first, at each end, leaving enough of the center portion unfinished, to be attached to the blouse neckline opening. Once the rouleaux ties were completed, I attached the bias strip to the neckline and finished it as a narrow bias binding using the same technique as outlined above under Bias Bound Seam. Instead of finishing it as a 1/4" seam binding I cut it down to 1/8". Although it was "fiddly" to turn under, the very narrow binding gave a beautiful finish to the neckline and matched the width of the rouleaux ties.
If your machine has a narrow buttonhole setting, use it to make buttonholes. Otherwise, try narrowing the stitch width of a preset buttonhole. To add support to the fabric as it is being stitched, place a piece of water soluble stabilizer underneath the fabric when stitching out the buttonhole. Afterwards, tear away the stabilizer. Apply a small amount of fray check to the buttonhole opening before using a buttonhole chisel to cut it open.