The ice cube trays trick also changed my life after my sister showed me. I even ended buying different sizes of molds to use depending on what I'm freezing.

During the lockdowns I also started with some more traditional preservation techniques like oils and vinegars. Not for long term storage (not enough space) but just for a couple days or weeks at a time. E.g. buying a bag of average quality olives then chuck them in a jar with good olive oil, fresh herbs, garlic, optionally things like chili and an orange rind. Yields both great olives as well as flavored oil for dressings.