For containers that may be hard to open, I cover them with Saran Wrap before placing the lid. This will help prevent spills when you go to open the container. This works for soups also.
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When measuring remember, wet foods like oil, milk, and water go in measuring containers that have room to spare at the top. For measuring dry foods such as sugar, flour, and oats, use cups that fill to the top so they can be leveled off.
