What is the best way to store loose tea to maintain its freshness?
Tea needs to be kept away from heat, light, air, and moisture. The best way to store tea is at room temperature in an opaque, airtight container.

Your container should not be plastic, because odors from previous uses (even if its only been used solely for tea) could contaminate your current tea.

Do not store tea in the freezer or refrigerator. Opening and closing of the door causes rapid humidity changes that cause moisture to seep into the container and degrade the flavor of the tea.

Some cheap tea containers can be found here: http://www.specialtybottle.com/teatincontainersmi.aspx

Personally, I would go for one with a twist or latching cover rather than a slip cover, just to ensure that it's airtight.

References


http://www.uptontea.com/shopcart/information/INFOstoring.asp
http://www.teavana.com/tea-info/tea-storage-for-loose-leaf-teas
http://www.teavivre.com/info/proper-storage-of-tea/
http://verdanttea.com/how-to-store-tea/