In a large glass jar, combine all the dried herbs and garlic, if using.
Pour the vinegar over the herbs and garlic and seal tightly. The vinegar is strong enough to corrode some metal lids, so in this case, consider putting plastic wrap or a plastic bag on top and then putting the lid on.
Leave in a cool, dark, place for 6-8 weeks, shaking daily if possible.
After 6-8 weeks, strain the herbs out using a small strainer and store the tonic in smaller jars for easy use.
Most herbs can be found locally, but are also available online.