With rising prices in eggs, i feel like I'm wasting my money away when a recipe requires only yolks or the whites. Do any of you have any ideas what to do with those extras left over?

With whites i know it can use on a sandwich or maybe scrambled whites lol. But the yolks my mind runs blank. Also sometimes I think about keeping the extras in the fridge just incase I do end up needed them for later. But it never happens, I also don't know how long they should keep for? Especially without being in the shell protecting them lol. So if anyone has any ideas up up for hearing them out.