Walk around an area with Bubotubers near a cauldron. Use Wingardium Leviosa on the Cauldron to lift it in the air, then move the cauldron towards the Bubotuber. A successful hit will explode the cauldron and the Bubotuber and clear the way. If the explosion is near a creature, they will take damage. The best place to try this at is Dragon Woods, near the dragon fly-by. This works best with one or more players.