Herbs require a potting mixture that is loose and lightweight, but not too rich. Excellent drainage is a must, as herbs won't tolerate wet feet, and the lack of oxygen to the roots can kill the plant.
Herbs will do well in any fresh, good quality potting soil that contains a mixture of compost or other organic matter, peat moss and perlite or vermiculite. Quality potting soils appropriate for herbs are available at most garden centers or nurseries.
A handful of clean, coarse sand will improve the potting soil's drainage. A light application of a time-release fertilizer added to the potting soil at planting time will provide necessary nutrients. Refer to the fertilizer container for specifics regarding rates of application for your particular herbs.