Historically, herbs have been planted in a dedicated area of the garden, usually with a design element included. Circles, wheels, and squares have all been used and may work in your yard. If not, plant your edibles among other plants. Avoid spraying your edibles with chemicals that you use in other parts of the landscape. Just another reason to go organic.
Evergreen plants are visible year round.
Consider these plants the bones or structure of the landscape. Its gray-green color adds contrast to the landscape. Perennial plants are planted once and return each year. These should be planted in an area you do not till so any amendments should be added at the time of planting. Cutting back each spring, top dressing with compost and adding a three to four inch layer of mulch will be the only maintenance required.