Whisk together the flour, salt and orange zest in a medium bowl.
In a large bowl, cream the butter, Crisco and sugar until light and fluffy. Beat in the egg, making sure it's fully incorporated. Then mix in the orange juice and vanilla.
Fold in the flour mixture on low speed, until just combined. Cover and chill the dough overnight in the refrigerator, for at least 8 hours.
Roll out half of the chilled dough on a lightly floured surface, until it's 1/4-inch thick. (Leave the rest of the dough in the refrigerator.) Cut out shells or desired shape, and use a lightly floured spatula to transfer the cutouts to a baking sheet lined with parchment paper or a silicone mat. Don't put more than 12 cookies on a baking sheet.
Re-roll the scraps, and then roll out the remaining dough. Place the baking sheets (with the cookie cutouts on them) in the freezer for 15 minutes or in the refrigerator for 1 hour before preheating the oven to 375°F (190°C).
Bake the cookies for 8 to 10 minutes, or until the edges are lightly browned and the cookies are set. Let the cookies rest on the pan for 5 minutes before removing to a wire rack to cool completely.