You can go both ways, first by breeding the offspring together, or then taking the first offspring, & breeding back to the parents. Go back, & forth with it to simply.
In the case of Malays, a breed almost extinct in the US, & genetic diversity dwindling, they need to be bred to unrelated bloodlines, or crossed with another breed to increase genetic diversity.
After being crossed, it's important to back cross to the purebreds to restore traits. But unrelated...