Mix vinegar, salt and pepper in a small bowl; let stand a few minutes. Slowly stir or whisk in oil. Taste for acid and salt; add more if needed. Stir to blend before using, or store in a jar with a tight lid in refrigerator; shake well before using.
Mustard French dressing: Add 1 to 1 1/2 Tablespoons Dijon mustard to the vinegar. Blend. Proceed with recipe.
French dressing with fresh herbs: Add 2 teaspoons fresh chopped herbs, such as basil, chervil or tarragon.
Chiffonade dressing: Add 1 Tablespoons minced parsley, 2 Tablespoons minced sweet red pepper, 1 Tablespoon minced onion, and 2 hard-cooked eggs, finely chopped.