This quick video provides a handy reference for using dry herbs when fresh herbs are not available. Celebrity Chef Fabio Viviani recommends a 3 to 1 ratio of dry to fresh. For example, if the recipe calls for 1 tablespoon of fresh oregano, use just 1 teaspoon of dry oregano (3 teaspoons in a tablespoon).
When using dry herbs, make sure they still have a nice, strong aroma. If not, add them to your compost heap and treat yourself a new container of high quality herbs.
While quality dry herbs can be pricey, a little goes a long way. Buy small bottles of dry herbs rather than the big, commercial-size (big box) containers. Yes, the larger sizes seem more cost effective but, unless you're working in an industrial kitchen, you'll simply won't be able to use them while they are still aromatic.
When your recipe calls for just a few ingredients, as most pasta dishes do, makes sure you use the absolute best quality you can find. The taste of the final dish will be so much more rewarding when you do.