Coriander seems to bolt when you are not looking so use and replace regularly.
Basil loves the warmer months so plant up lots for summer pesto?
French tarragon is now available.
Stevia has been really popular for a natural sweetener.
Don't forget companion planting such as marigold and calendula to get the best out of your vegetables. Colour up your salads with calendula petals, borage flowers and nasturtium flowers.
Rosemary stems make great kebab sticks for lamb. Soak them in water for an hour to prevent burning.
You don't have to restrict you herbs to their own bed! Plant amongst your shrubs as well.
Regular watering will keep your herbs healthy.