I place the uncooked meatballs on a flat sheet covered in wax paper until frozen. I then transfer them to a Ziploc–since they’re already frozen at this point, they don’t stick together–which has been labelled with “meatballs” + date. When I want to use them, I brown them and then add fresh sauce. I’ve been doing this for decades (OK, so the labeling has been a relatively recent addition 
I was taught that you shouldn’t thaw ground beef, but rather cook it from the frozen state. Now that I think about it, I’ve never actually looked at the science/thought behind this. Just one of those things mom said that I never questioned.
