If you have several children, and raise them to well-adjusted adults who have children of their own, the chances are already very good. Assuming your average descendant has more than one child, and inbreeding is negligible, the number of descendants increases exponentially by generation. So the probability that none of your descendants in a given generation breed falls off rapidly.

Of course, if you can father hundreds of children, that would also work. But you would probably run a much higher risk of being killed or imprisoned before you can spread your genes around much.