In a large bowl, together the flour, baking soda, and salt. Set aside.
Using an electric mixer, beat the butter and sugar until smooth. Add the egg and beat until fluffy, about 2 minutes. Beat in the vanilla.
With the mixer on low, gradually add the flour mixture, mixing until just incorporated . Shape into a disk and refrigerate, wrapped, for at least 1 hour and up to 3 days.
Make cookies according to directions in the 10 Ideas For Sugar Cookie Dough collection. Alternately, make cutout cookies by doing the following: Heat oven to 350° F. On a floured surface, roll out each disk ¼ inch thick. Cut into shapes and place on parchment-lined baking sheets; refrigerate until firm. Sprinkle with decorating sugar, if using, and bake until just beginning to brown, 12 to 15 minutes.