Any or all of the following:

A clean, dry kitchen towel

Very warm tap water--heck, make it hot, so long as you don't burn yourself or others.

A large kitchen knife (or object of similar weight and dimension, such as a metal spatula or bottle opener). It doesn't have to be sharp, because you won't be using the blade.

Give each jar-opening strategy about five minutes before moving on to the next one.

2torial #0489: Learn2 Open a Jar Lift that lid...without flipping yours! Things were going just great in your kitchen. Then you tried to open that innocent, perfectly functional-looking jar: now there's a thin corkscrew of metal holding fast between you and your bliss. Stuck? In a jam? Here are a few handy hints for loosening that lid. Wash your hands. Often our hands have a natural, oily residue which makes it difficult to get a good grip on slick, metallic things. Wash your hands with a mild detergent and dry them thoroughly on a clean towel. Wash the jar. Jars, especially those lurking at the back of the shelf over the stove for weeks or months, may have accumulated an oily residue from kitchen grease and smoke. Paying particular attention to the lid, rinse the jar under warm water to loosen and remove any oily residue. Use a drop or two of liquid detergent if the jar feels particularly greasy, and dry thoroughly with a clean towel. Step 1