I always have put them directly in the tin and then sealed/closed the tin lid with a strip of duct tape.  They seem to keep fairly well in the tin.  Although they WOULDN'T be water protected in the tin as I have it setup, this may be a problem...
I don't know if this is the best way to do it, it's just the way I have done it.  I once was like you...asking "what is the best way" and I just made something work that seemed to make sense.
 
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"By failing to prepare, you are preparing to fail."  - Frankin