As with upshifting, downshifting can wear out your clutch (along with myriad other components) if done incorrectly, but you can save wear on it by doing one of two things: the BEST for your car would be a double clutch, where you shift to neutral, rev the engine to the rpm appropriate for the gear your shifting to with your speed, then shift to the appropriate gear; just make sure you DO let the clutch out after moving to neutral. Not only does this save the clutch (since you're not burning it to rev the engine), but it also saves your syncs since they don't have to spin up your transmission. A less complicated but almost as effective solution is to just to rev up the engine between the gears. While this will still save the clutch, it will still put the downshifting wear on your syncs.
Just a thought
