Normally I don’t bother balancing 12 inch and smaller tires. I just haven’t felt a difference on such small diameter wheels. If your tires have either a red or a yellow mark, on the sidewall, from the factory. A yellow mark shows the lightest side of the tire and a red mark will denote a heavy spot on the tire. If you have a yellow mark line it up with the valve stem. The valve stem is most likely the heavier side of the rim. If you have a red mark on the tire, line it up 180 degrees opposite the valve stem.