First off, I would be using two flies. I generally put the anchor fly at the point. For short leader fishing I use a five foot butt section to which my tippet is attached to it. If you search youtube you will find out video of the Davy Knot for tying your leader sections.
For attaching the flies, use a surgeons knot and attach your flies to the tag end that goes towards your point fly.make sure that the flies are around 20 inches apart.