Cream butter and sugar. Add vanilla and egg. Sift flour, soda and salt together; mix into butter mixture. (Dough will be stiff.) Working with a small amount of dough at a time, roll out very thin, between sheets of floured wax paper. Cut into desired shapes and place on greased cookie sheets. Sprinkle with sugar and bake in 375-degree oven for 10-12 minutes. Makes approximately 6 dozen cookies.