>>2754046i suggest something like pic related, $1.50 for 50 on amazon for me right now
you might want a slightly larger size depending on what diameter line and how long a leader you're putting in them
if you fish in strong wind or in the surf you might want a proper leader wallet like fly fishermen use, these are pretty easy to drop and lose
sandwich bags are fine too but a bit big for one leader and i wouldn't recommend trying to put multiple coiled leaders in one bag; they'll just end up tangled together
