How to take good dance pictures?

Hi! How can I take good dance pictures? My friends and I were going to have a photoshoot, hoping to get good pictures of side aerials, front aerials, tucks, tilts, leg holds, calypsos, barrel turns, drop tilts, knee drops, etc. We will be using iphones… Do you have any tips on taking motion pictures with an iPhone?

Take a video then pause & screen shot.