Sweep a cotton ball of 100% lemon juice on stripy areas. Citric acid from the lemon is a natural skin lightener and exfoliator. It smooths away unevenly applied tanner by sloughing off overly tanned skin cells. You can also massage plain baking soda onto damp skin in small, gentle circular motions. Like lemon juice, baking soda will slough off freshly dyed cells & reveal untanned skin underneath.