IMO, softies are one of the most difficult to frag because getting them attached to a plug or rock can be difficult. Most of them produce a mucus coat so you can't just glue them directly. I like to glue a plastic toothpick into a hole in a rock, then skewer the soft coral, then cap the skewer with a bead of superglue gel to keep in from slipping off. After time the coral will grow to attach to the rock, as well as encapsulate the toothpick.