Excess smoke from a wood-wick candle can be caused by using too much fragrance or dye, a wick that is too large or not trimming the wick before each use. To reduce smoke, make sure to only use the recommended amount of fragrance and dye, choose the appropriate size wick for your jar and trim the wick to 1/4 inch before each use.
Additionally, make sure the wick is properly centered in the candle to prevent it from burning too close to one side of the jar.