Clean a 16 oz. mason jar with hot, soapy water thoroughly, and dry.
In a small saucepot, stir together the vinegar, water, sugar, and salt. Bring liquid to a boil, then reduce heat to low and cook for 10 minutes. Allow to cool for 5 minutes before pouring in jar.
While liquid is cooking, pierce each cherry tomato with a toothpick (the more you pierce the skin, the more 'pickle-y' the tomato).
Place tomatoes in the jar with desired add-ins, then pour pickling liquid over tomatoes, leaving a half-inch of space.
Cover and refrigerate for at least 3 days, and up to 1 month.
