Egg whites provide the protein from eggs but don't contain the cholesterol found in egg yolks. That's good news for your heart.
Eggs separate more easily when they're cold, but whites beat to a higher volume at room temperature. So, separate cold eggs and allow the whites to stand at room temperature 15 minutes before beating them.
To prevent mixing yolk into the whites, crack eggs, one at a time, and place each white into a custard cup to ensure it is free of yolk before transferring it to the mixing bowl.
Meringue cookies do not freeze well; give extras away as gifts and store your share in a loosely covered container at room temperature.