Position 1 rack in bottom third and 1 rack in top third of oven and preheat to 200 degrees. Line 2 large rimmed baking sheets with parchment paper. Using a 4 to 5-inch bowl as template and spacing 2 inches apart, trace 4 circles on each parchment sheet. Turn papers over on baking sheets.
Beat egg whites and cream of tartar in large bowl until soft peaks form. Gradually add sugar, beating until whites are stiff but not dry. Fold in coconut or zest, if desired. Drop batter in center of each circle and spread to fill.
Bake meringues until dry, about 3 hours. Turn off oven and leave maringues in oven for another hour. Cool and peel off parchment paper. When not sticky, layer in parchment paper and put in zip-locks. Mades 8.