At around £0.80 a pop it really is a shameful waste. In particular after cooking a curry or other exotic fare with 3 or 4 different kinds of herbs.
If you are to use the same herb again in the week; the easiest trick is to place a kitchen paper on your counter, wet your hands under running water and transfer onto the paper.
You then wrap the herb in the paper; pop it back in the bag and it will keep fresh for up to a week.
When you know the herb will only be used later. (This will not work for salads but great for sauce, stocks and soups)
Chop it as coarsely or thinly as you wish and fill an ice-cube tray to about half with the chopped herbs.
Cover with water. Freeze and transfer to marked freezer bag.
Don't forget to keep the stems to flavour soups !
You can keep the herbs for about 4 weeks this way. And you will find you use more of them to flavour soups and sauces as they are so readily available ;-)