You might try using it right after you get out of a hot shower, and use it on hairs that are about one-fourth of an inch long or so. Hairs tend to break if they're too long.
If they still seem to break, some people's hairs seem to come out better before the shower. I know, conflicting advice, but it seems like after a shower makes the hairs stretch a little better without breaking. Not true for everyone, though.