I've done some reading on it, and yes all methods will take away some potency. Thats why I wouldnt do alot, maybe a small bud, big enough to pack a bowl or something. Best method is to use dehydrator if you have one. One way is to put it in the microwave and run if for 30 secs or so. Check it and flip it. Repeat until dry. Another way is to set on your coffee burner, turn it every ten minutes or so until dry. Micro is fastest, burner takes about 30 minutes or so. Paper bag will take a day or two, maybe longer, and will hurt the potency more. Here is link for quick dry:
http://www.marijuanagrowguide.net/Quick_Dry_Techniques.html