You don't need to put spouse and/or children on the payroll. You can issue them non-voting, participating shares in your professional corp (separate classes for spouse and children) and then declare dividends as needed.

Thus, for example, if your child has school fees to be paid, instead of you paying for them out of your after tax income, you pay the child a dividend sufficient to pay the school fees but small enough to avoid or minimize tax consequences and the child pays her school fees herself. Presto!