In small mixing bowl, beat egg whites with cream of tartar at high speed until foamy. Add sugar, 2 tablespoons at a time, beating constantly until sugar is dissolved** and whites are glossy and stand in stiff peaks. Beat or fold in variation ingredients, as desired.
**Rub just a bit of meringue between thumb and forefinger to feel if sugar has dissolved.
Drop by rounded teaspoonsful or pipe through pastry tube onto greased or lined (foil or waxed, brown or parchment paper) baking sheets. Bake in preheated 225 degree F. oven until firm, about 1 hour. Turn off oven, let cookies stand in oven with door closed until cool, dry and crisp, at least 1 additional hour. Store in tightly sealed containers. To recrisp, bake in preheated 200 degree F. oven about 15-20 minutes.
*VARIATION INGREDIENTS: Use amounts listed for 1 batch of cookies. To make 2 variations at a time, divide egg white mixture equally between 2 bowls. Beat or fold 1/2 of the amounts listed for 1 of 2 variations into each bowl.
Brandy Alexander: Beat in 1/4 cup unsweetened cocoa, 1 teaspoon vanilla and 1/4 teaspoon brandy extract.
Cherry Almond: Fold in 1/2 cup chopped drained maraschino cherries and 1/2 cup chopped almonds.
Chocolate Nut: Beat in 1/4 cup unsweetened cocoa and 1 teaspoon vanilla. Fold in 1/2 cup chopped nuts.
Citrus: Beat in 1 tablespoon grated orange peel, 1/4 teaspoon lemon extract and a few drops yellow food color.
Coconut Macaroons: Beat in 1 teaspoon vanilla. Fold in 1/2 cup flaked coconut. Drop by rounded tablespoonsful. Bake in preheated 325 degree F. oven until lightly browned, about 18-20 minutes. Cool Slightly before removing to wire racks. Cool completely.
Mint Chocolate Chip: Beat in 1/4 teaspoon mint extract and a few drops green food color. Fold in 1/2 cup semi-sweet chocolate pieces.