Saw these cute little bottles at Michaels and I couldn't resit them. They also had some really pretty sea glass on sale as well... Needless to say I got that to. So the process is super simple:
1. Smash glass lightly with a hammer to break it into small enough pieces to fit in the tiny bottles. I wrapped mine in fabric before so it wouldn't fly everywhere.
2. I put a few shards in each bottle, mixed the colors in some and tried to use only shades of one color in another. I also put a little bit of fabric scraps from another project in each bottle
3. When done filling bottles, put a little glue on the rim of each bottle before you put the cork in. The screws I just got at Ace hardware, and screwed them in by hand
4. I used embroidery thread for the string, but any kind will work!