One way is to heat up a teaspoon over a stove burner and touch it to the end of the fiber.

You can use a butane lighter, candle, match, whatever. But you only want to soften it not melt it (which would blacken the end). You soften it enough to be able to form a tiny head. But I like Semisane's method better. Then for sure you won't blacken the end.

thanks for the info guys.