Heat oven to 350ºF. Remove half of cookie dough from package; refrigerate remaining half of dough until needed.
On lightly floured surface, roll dough 1/4 inch thick. With 3- to 3 1/2-inch cookie cutters such as diamond, heart or star, cut out dough shapes for birdhouses (or cut desired shapes from dough with knife). Use 1-inch canapé cutter or sharp knife to make "door" in bottom half of each. If desired, use drinking straw to make hole in top of cookie for hanging. Place 3 inches apart on ungreased cookie sheet. Repeat with remaining half of dough.
For decorations on birdhouses, roll scraps of dough, and cut miniature shapes such as trees, stars and other small shapes; do not attach to birdhouses. Place miniature shapes on cookie sheets.
Bake 7 to 11 minutes or until set (bake small shapes about 7 minutes). Carefully remove from cookie sheet; place on cooling racks. If necessary, re-poke holes for hanging. Cool completely, about 20 minutes.
To decorate cookies, use vanilla frosting to attach small baked shapes to birdhouses. Attach pretzels for roofs. Cut each unwrapped candy into 4 lengthwise pieces; attach 1 piece with frosting below door to look like perch. Use vanilla frosting or decorating icing to make snow on roofs. Use decorating gels and baking bits to add decorations or words to birdhouses.