So you've gone all out and made a great recipe that called for egg yolks only. It came out great, but what did you do with all the egg whites? If you normally toss them in the trash, then it's time to rethink your strategy. Egg whites can actually be frozen for future use. Simply take a clean, empty ice cube tray and put one egg white per cube. When they're frozen, take the cubes out and put them all in a ziploc bag. They will last about 3 months, and need to be defrosted in the refrigerator before using (about 8 hours).
If you have leftover egg yolks, you can freeze those also, however a lot of chefs don't recommend it. If you do freeze them, you will have to stabilize them first (if you don't, they may become too thick to use). To do so add 1 tablespoon of sugar or honey per pint of egg yolks or 1 teaspoon of salt per pint of egg yolks. You can decide on sugar or salt depending on what recipe you're going to use in the future. If it's a savory dish, then add salt, if it's a sweet dish, add sugar. The stabilized yolks can then be frozen like the whites (1 tablespoon = 1 egg yolk). To use the yolks, remove from freezer and let them thaw in the fridge for about 8 hours. They will also last about 3 months.
Note: These will not look the same as fresh eggs, but with proper storage and handling, your results should be the same.