As far as finding the right balance of the amount of fragrance to wax, it truly depends upon personal preference and desired hot throw. However, a general rule of thumb for strongly scented candles is 6-7%.  Use the recommended percentage of fragrance oil for the type of selected wax. For soy candles, for example, is 7-10%.
The wax can only absorb a certain amount of fragrance oil, so make sure to check you are not exceeding the recommended amount.
Most waxes will hold no more than 12% of fragrance oil however to assure the candle stability is not compromised we advise using 10% fragrance oil for optimal scent throw.