What mixture make the best bubble solution?

Use surfactant product e.g. Shampoo, Dishwashing liquid or Detergent. Soap can make to bubble agent but not as good as surfactant base product. You can distinguish between soap base and surfactant base by its' opacity. Clear Bath gel is surfactant base and Turbid bath is mostly soap.

It should dilute Shampoo or Dishwashing liquid or Detergent with water approximately 1:5 to 1:10 ratio. Ratio might need to vary depend on surfactant product you use.