I purchased a bagful of both from Costco and got to work on the onions slicing off both ends and peeling off the skins. Because of their size, I quarter them.
The last step is packaging up those chopped onions into freezer bags and off to the freezer they go.
Other items I always store in my freezer: Shredded cheese, sliced cheese, 2% milk, bacon, cream cheese, bread, chicken, meat, fish, and anything else that will freeze goes in.
It's what works for me.