Ideally (depending on what you have available) something hard and red for the ass spanks (old table tennis bat/paddle would be ideal). Make sure it's something that hurts though so you learn a lesson (your butt's redness is more important than the objects redness
)
For the balls spanks then, well let's be honest, anything will hurt. If you were favourites for the match (not sure if pre-match odds are displayed, if not then if you're at home), but still had less than 50% possession, then use a wooden spoon. If you were underdogs (or away) use your hand.