Add dressing ingredients to a medium bowl and whisk together thoroughly. Taste and adjust as needed so the dressing suits your tastes. Note: some balsamic vinegars are a lot sweeter than others, so start with half the amount of sugar suggested, taste, and add more if needed.
Transfer to a jar and refrigerate for up to a week. You can eat it right away, but I prefer to leave it for a few hours so the flavors meld more and the dried herbs soften up.
Notes
The recipe makes just under one cup of dressing, so it will work for 1-2 larger salads or about 4-6 smaller ones (of course this depends on how much dressing you use and how big the salads are).
For the nutritional info, one serving is about 1 tablespoon.