I'm not going to lie, needle-felting is kind of a dangerous craft. Poking a notched triangular-tipped needle, several times per second, within millimeters of your fingers, is asking for trouble.
I go through periods of time where I rarely stab myself, but sometimes there will be a week when I draw blood from my fingertip or the side of my finger several times. But recently, I began stabbing through my thumbnail. Four times in the span of a few weeks. One time, the needle went into the same spot it had poked through before. Mind you, I have been needle-felting for nearly four years, and this had never happened before last month.
So I finally decided to do something about it. I went to the store and bought the most glitter-filled nail polish I could find. And I put several layers of it on my thumbnail. Fixed!
It's already proven itself, too! We needle-felters should start a trend. It's like the manicures with the contrasting color on the ring-finger nail. But this one has a purpose!