Leaves :

Delicate-tasting or tender-leaved herbs tend to lose some flavour in drying. Freeze them whole or chopped and store in containers in the freezer. Also freezing in ice cube trays is a good method. Puree herb leaves and a little water or olive oil (depending on the recipe), pour into ice cube tray and freeze. Store in containers in freezer and pop into your spagetti sauce, stew, soups. Examples are lovage, basil in oil and water, French tarragon, chives.

Flowers :

Borage, rose petals, carnations (whole or petals depending on the size) are examples of flowers that I freeze in ice cubes. A hint to avoid floating flowers: pour water up to one half of the ice cube tray with the flower in it, freeze, then add water to the top and freeze again. Store in containers as needed for herb iced teas and drinks.