Store your herbs in a cool dark place away from direct heat and sunlight. Keep them tightly closed. I store my herbs in a box high in my closet. Each herb is either sealed in it's original package, or double bagged with a ziplock bag as the outer bag. My house is never too warm, and being that summer is approaching the central air will be on- since it comes out from the ceiling I have no doubt that my herbs will stay cool.
I don't feel the need to bag them any differently than I do, because I try to buy as much as I will be using in no more than 6 months. This way they remain fresh and I don't have to worry about what's about to expire because everything ( of that one particular herb) was purchased around the same time and has the same expiration date. I generally don't use henna or herbs more than a year old. But there are some exceptions, especially when it comes to nupur henna ( that I may or may not be using any longer) that has an expiration date on it.
The box I use is from a local Burlington Coat Factory store, that sells waaaayy more than coats nowadays. There were a few to choose from and this box is very sturdy at only $7.There are not just herbs in here, as I store my henna gloves and bowl, along with my extra cocoveda, camellia, and amla oil here too!
This box was a great find, serving as a wonderful way to keep my herbs accessible and aesthetically incorporated into my room's decor. How do you store your herbs?