Can I make Italian meatballs in advance?

This is all super helpful.
Does anyone know if they still remain moist?
BTW My moisture comes from an egg, and white bread soaked in grated onion - will they still be moist if left in fridge and browned later, before adding to sauce? I also have parmesan, herbs, and salt. I am told salt draws out moisture, that's why I am asking?

Honestly, I would make the meatballs ahead of time (i.e. make the meat mixture and shape into balls), but not cook them til the day you'll be serving them. You can make the sauce ahead of time--totally better the next day--but I would cook off the meatballs the day of. They don't take long to cook, and having them ready to go is more than half the battle.

And re-heat slowly.

Agree w/ the above answer; however, make sure to use good, airtight, non-plastic containers for both the meatballs and the sauce to enhance flavor and freshness.

You can make meatballs in advance. You can cook them and then add to the sauce after you brown the meatballs. A day and a half is not a problem to keep the meatballs and sauce fresh. Actually, the flavors of the herbs and spices will develop nicely with a little time. The "better the next day" rule applies here!