You probably wouldn't think that nail polish is the best thing when it comes to sewing and you may not even be able to think of how it could be used in sewing. However, it can be extremely handy in the world of buttons as it helps to keep the buttons sturdy on your clothing. You just need some transparent nail polish to paint on the threads and you are good to go.
The nail polish helps to keep the threads from fraying and keeps the buttons secured for a longer period of time.