I have had the pleasure of helping several families craft a family crest. A few of these came as clients for engraved Bibles and other customized Family Worship materials through The Forge Press, and others are simply friends who wanted a crest.
Each crest includes multiple icon designs, plus layout decisions to combine a full heraldic achievement. I've been able to create a few "templates" for the repetitive elements of the achievement, but the other elements are generated fresh for each family.