Funny, I just recently went through this myself. Use 100% cotton balls, with vaseline rubbed onto them (about a fingertip full, with the large cotton balls). Coat the outside, seal in something. When you use them, break the cotton ball open, to get to the dry center. Shoot the sparks into it. It will catch, and the vaseline will keep it lit for quite some time.
I just experimented with this last week, and did it incorrectly. I asked here AFTER the fact. Now, I'm passing this on to you <img src="/images/graemlins/smile.gif" alt="" />