I store tea in Planetary Design Airscape Storage Canisters. The setup consists of an 18/8 stainless steel bucket with two lids. The inner lid is a plunger that evacuates air inside the can down to the level of the contents. The outer lid just sits on top of the canister, providing a platform to allow other canister to be stacked on top. The bottom of the bucket has a silicon pad that improves stackability. All together its a nice system for keeping things fresh.
It comes in two sizes: medium and small. Medium is good for unrolled leaves with body (like Mi Lan Xiang) or something you want to store a lot of (like Hojicha). Small is good for something with leaves that are flat (I like keeping Pre-rain Dragonwell in stock), rolled (might I suggest Jin Xuan), or otherwise compact. I wish there was an even smaller size. Alas.
They are not appropriate for pu-erh, which needs to breathe. But for the teas I like to stock in my pantry, they’re great. I’ve been using them for about three years now, and I do think they help extend the shelf life of my supplies.