Put washed and dried whole herbs or vegetables in a bottle or other container, preferably glass, and pour in vinegar until filled.  Steep for 4 to 6 weeks for full flavour before removing.

Combination Suggestions:

Red Wine Vinegar:  Shallots, garlic cloves, tarragon
White or Cider Vinegar:  Dill, Mint, Lemon Peel, Thyme, mustard seed, Lemon Grass (I’ve had luck with sage and basil as well.)
Rice Wine Vinegar:  Peeled ginger, green onions