Whisk vinegar, mustard, and syrup until smooth. Slowly drizzle in olive oil, whisking constantly until vinaigrette is smooth. Season with salt and pepper to taste.
Balsamic Maple Vinaigrette:
Omit the white vinegar and the agave syrup. Add balsamic vinegar and maple syrup to vinaigrette ingredients and whisk until smooth.
Orange Ginger Vinaigrette:
Reduce vinegar down to 2 tablespoons and omit agave syrup. Whisk orange juice and ginger into vinaigrette ingredients until smooth.
Roasted Garlic Parmesan Vinaigrette:
Whisk roasted garlic and Parmesan cheese into vinaigrette ingredients.
Raspberry Basil Vinaigrette:
Omit agave syrup and whisk raspberry jam and basil into vinaigrette ingredients until smooth.
Curry Apple Honey Vinaigrette:
Omit agave syrup and white vinegar. Whisk curry powder, apple cider vinegar, and honey into vinaigrette ingredients until smooth.