Send a Luma out with the Luma Shot, or use it when the Luma is far away to call it back in. The Launch Star is an excellent recovery move; it deals no damage, but it covers a ton of distance in the air. Use Gravitational Pull to pull in items, grab thrown items, or nullify projectiles. The Luma will get KO'd after too many hits or after being pushed off the edge. It takes 13 seconds for another to respawn.
*All pictures of moves for all characters are gathered from official sources and from pictures and videos without detailed explanations, and some are subject to change.