Pendant Thread Cutter Antique Silver: The Clover Thread Cutter Pendant is the most convenient way to snip thread.
A little over an inch in diameter, it has a hole for a chain or ribbon, and notches all around the edge with a cutting surface deep in the notch. Run your thread over one of the notches and you will have a clean cut.
The notches are small enough so it is impossible to cut yourself. Perfect for airline travel, too!