Years ago I used a strange method that required stringing oregano inside a paper bag and poking air holes throughout. It took forever. Now I use the oven-drying method I found on Preserving Your Harvest.
I think the resulting flavor is better than what I remember from the paper bag method. Maybe it's because the oven-drying process happens quickly, within minutes, rather than over many days.
Crunch a few crispy oregano leaves into your favorite sauces. So much better and cheaper than store bought herbs!