I found a tutorial on how to sew on Shisha mirrors in the blog which is the sequel of In a Minute Ago.
The best of this technique is, that you can use it to sew on other items, too, such as coins e.g.
I really must try it sometime.
Links:
Take a Stitch Tuesday Week 35 – Shisha stitch
In a Minute Ago with lots of information, e.g. the Dictionary of Stitches for Hand Embroidery and Needlework and the I dropped the button box crazy quilt.