(Source: "Epicurious" https://www.epicurious.com/expert-advice/how-to-make-homemade-salad-dressing-from-basic-to-fancy-article)
Process in food processor/blender for smoother dressing.
To make a bare-bones vinaigrette all you need is vinegar (sherry, champagne, balsamic, red, white, or rice wine vinegar) and oil (go with a neutral vegetable oil like grapeseed for a mild base, or your best extra-virgin olive oil for grassier undertones). Traditional vinaigrette recipes call for a ratio of three parts oil to one part vinegar. However, some people—like me—prefer their dressings to pack more punch and choose a 2:1 oil to vinegar ratio. Some vinegars have a higher level of acidity than others, so it's always a good idea to sample your dressing and adjust accordingly.
To make your vinaigrette, whisk a little kosher or fine sea salt into some vinegar until it dissolves. Start with about 1/4 teaspoon salt per tablespoon of vinegar. Keep whisking and slowly drizzle in double the amount of oil as vinegar, then taste. I like to dip a lettuce leaf into the dressing to see how it will taste in my salad instead of tasting it on its own.
If desired, gradually add more oil, tasting incrementally, until you achieve a balance of acidity and fat you enjoy. This two-ingredient dressing will never fully emulsify, but vigorous whisking will hold it together long enough to dress your salad (just shake or whisk again before serving if you make extra to enjoy throughout the week). Finish the dressing off with some freshly ground black pepper.
A note on citrus: lemon, lime, orange, or grapefruit juices lend a lovely brightness when subbed in for a portion of the vinegar in a vinaigrette. But, like the name indicates, this dressing has to include vinegar to be considered a true vinaigrette.
Emulsify with Mustard
Ready to take your dressing to the next level? Add mustard to your vinaigrette and watch emulsification magic happen. When whisked or blended with mustard, oil and vinegar suddenly synthesize into a smooth and creamy concoction. Add about 1/2 teaspoon of Dijon or grainy mustard per tablespoon of vinegar.
Sweeten the Pot
The key to a tasty vinaigrette is striking the right balance between the levels of acid and fat. Incorporating a sweetener like brown or white sugar, honey, agave, maple syrup, or molasses can soften the acidity of the vinegar. Add the salt and your sweetener of choice (a little goes a long way, so start with just a pinch of sugar or 1/2 to 1 teaspoon liquid sweetener for every tablespoon of vinegar), whisk to dissolve in the vinegar, then incorporate the oil. You might not need as much oil because the sweetener will round out the sharpness of the vinegar, which is a bonus for those watching their fat intake.
Add An Allium
Alliums like garlic and shallots play very well with oil and vinegar. Work wonders by integrating a finely chopped garlic clove or spoonful of minced shallot into your dressing blend. If the taste of raw garlic is too intense for you, try poaching a peeled clove in simmering water for three minutes to remove some of its bite. To tame the onion-y flavor of shallot, soak it in the vinegar for at least five and up to 15 minutes before adding the rest of the ingredients to your dressing.
Fresh or dried herbs make vinaigrettes shine. Try any herb (or mix of herbs) you have on hand: basil, thyme, parsley, dill, oregano, marjoram, mint, tarragon, rosemary, cilantro, and chives are all great choices. You'll need about 1/2 teaspoon dried or 1 tablespoon fresh chopped herbs per tablespoon of vinegar. You can always add more to taste.
Spice It Up
Enliven your vinaigrette with toasted crushed or ground spices like red pepper flake, cumin, coriander, smoked or sweet paprika, fennel, or poppy seeds. Mix in 1/4 to 1/2 teaspoon spice per tablespoon vinegar. These flavor additions are especially nice with grain or lentil salads, grilled or roasted vegetables, or in marinades. Or make a garlic and spice-infused oil, let cool, and whisk with vinegar and any other elements you choose.
Regardless of how far you take your vinaigrette, a few standard rules apply. Make a little at time—just what you need for a meal—or make a lot. It will keep for three days or longer in the fridge, depending on the shelf life of the ingredients you choose. You can store your vinaigrette at room temperature if no fresh ingredients like herbs or alliums are included.
And vinaigrettes aren't just for lettuce; They can be a great marinade for meat, seafood, or vegetables. Or serve your vinaigrette with bread for dipping, drizzle it over sliced fresh tomatoes and mozzarella cheese, use it as a sauce for steamed artichokes, or toss with roasted or grilled vegetables like asparagus, potatoes, eggplant, and summer squash.
1/2 cup olive oil
1/4 cup fresh lemon juice
1 garlic clove or 1 shallot, finely chopped
2 tablespoons Dijon mustard
1 tablespoon honey
4 tablespoons chopped fresh sage
(Source: "NPR" https://www.npr.org/2011/06/07/137035685/catch-all-herb-salad-with-lemon-sage-vinaigrette)