I have a bunch in mason jars (I have dozens of jars in different sizes), I have some in airtight plastic pill type cases and I also do the electrical tape thing rustilley mentioned.

I ordered a ton when I started and I still have a whole lot left.  Some of the ones in the plastic containers have picked up just a hint of a plastic scent after like 2 years, but it’s all still reasonably fresh and pleasant to take.  The mason jar stuff is still great after years, though I make sure not to open the jars that often.