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!
It works well and is easy to keep track of if you choose to wear it around your neck and it takes up much less space than scissors in my tiny notions bag. And, TSA is not going to take this away from me!