I am not aware of any method of freezing herbs that will maintain their freshness, in the general case, especially for delicate herbs such as basil.
The best method I know of to freeze herbs, which I personally would not do and have never tried, is to mince or puree the herbs, then freeze them with water. You might do the freezing in an ice cube tray to have small quantities available. The water is to help prevent the volatile flavors from evaporating, which will happen slowly even at freezer temperatures. Of course, this is still very different than fresh.
I will try to answer the alternate question which is probably what you really want to know: what is the best way to hold fresh herbs to maintain their quality?
The best way to hold fresh herbs is to treat them like a bouquet of flowers. Trim the bottom of the stem ends, so there is a fresh, clean cut. Then put them in a small drinking glass, measuring cup, or other container with water, much like you would put flowers in a vase. The entire thing can then be put in the refrigerator (florist storage rooms are refrigerated, too!). With this technique, you will often be able to get a week or more. (BTW, it also works wonders with celery, which is essentially a giant big herb.)
Probably the second best way is to layer the herbs in a single layer in paper towels, then roll or fold that up so you can put it in a zip lock bag that is not completely sealed (you don't want the moisture from their respiration--herbs are still alive on the stem--to be stuck inside). This too would go into the fridge. You should get at least a few days with this method.
With either method, you can wash the herbs before storage, but with the paper towel method, they should be thoroughly dried after being washed.