Fire + Wind - They don't mix, but they work together, wind can be used to power up fire.
Earth + Wind - Sand comes to mind, because Shukaku is shown being a Wind Type.
Lightning + Wind - Hmm...storm element comes to mind.
Lightning + Fire - This is like combining Ice with Water, Lightning is simply highly compressed fire.
Lightning + Earth - They don't go together, considering Earth not being a conductor for Lightning, making it a complete dud.