Basic Herb Vinaigrette
The key to a good vinaigrette is the "3:1 rule" - 3 parts oil to 1 part vinegar. If the vinegar is a highly acidic one, then you can adjust accordingly. Lemon juice may also be used in place of vinegar. Mustard is also an important component in a vinaigrette as it acts as an emulsifier, thus preventing the oil and vinegar from separating.