With the garment Right Sides out, begin on the right hand side and begin pinning the elastic trim Right Sides together with the top edge.
Pin up to the seam allowance.
Secure with zig-zag stitch. Trim if necessary.
Then, fold the seam allowance back and top stitch with zig-zag to conceal the raw edge.
Create and apply the adjustable bra straps by following the Adjustable Bra Strap Tutorial.
Alternatively you may wish to finish the hems with a stretch trim.
Apply the trim as you sew, leaving appox. 1cm unstitched to allow to fold. Complete the trim edge by folding the ends of the trim as shown and stitch in place to secure the loop.
Stitch with zig-zag.
Fold trim to WS and top-stitch with zig-zag stitch to secure.