Most herbs are simple to freeze. Smaller plants like thyme (tanacetum vulgare) can be frozen on the stem, and basil (ocimum basilicum) needs to be blanched or it will turn black when frozen. When in doubt, go ahead and blanch herbs, as it will help retain color and flavor.
Blanch herbs by holding them by their stem with tongs and briefly dipping them in boiling water. When the colors brighten, remove from water.
Spread herbs, either chopped up or whole, flat on a baking sheet, and put it in the freezer. When frozen, collect them in a large freezer bag, marking the outside of the bag with the name of the herb so it is easier to select for use later.
Puree herbs as an alternate method of freezing. Take the herbs and blend them with just enough water to make a paste-like substance. Pour into an ice-cube tray and freeze. Keep these in freezer bags just like the normal herbs, and later use them in soups and stews with ease.
Frozen herbs are easier to use in soups and cooked dishes, but if you want to use them in salads, thaw them out first and pat them dry.