Basil is one of the most common cooking herbs and it can also add a great accent in the garden. Dark purple varieties provide beautiful color and make a nice contrast to the standard green varieties. Basil is an annual herb that needs full sun and regular water. If you're using basil in cooking, you don't want to let it flower and go to seed, as the flavor weakens and the plant becomes spindly. Pinch off the tips of the plant, removing flowers when they develop.
Rosemary and Lavender
Lavender and rosemary are perennial shrubs that require little maintenance once established. Rosemary is easy to prune or wire into any shape you desire. It enjoys full sun and good drainage, needs little water once established and requires little or no fertilizer. Lavender can make a unique hedge. The plants will grow in mounds with little flower heads peaking up over the top. Plant lavender in an area with good drainage and trim 1/3 of the plant back after it blooms, thinning out the stems at the same time.
English thyme is the most common variety available at nurseries and it makes a great groundcover in the garden. Lemon thyme is also readily available and has the added benefit of the lemon fragrance. If you're going to use thyme in cooking, make sure to ask if the variety you buy at the nursery is edible.
Chives grow in clumps and have grass-like leaves and pink or purple flowers that will pop up between 12-14 inches tall. This makes for a nice accent plant interspersed throughout the garden, used much like you would an ornamental grass. The flowers will attract bees and the onion smell has been known to repel some pests. These plants can act as a protective border for other plants, blocking out the enemy and inviting friendly bees in.