How to properly store pickups

Alnico degausses/regausses (spell check tells me neither is a word, but you get what I'm saying) incredibly easily. (If I wanted, I could change my strat pickups from S to N just by waving one of my 1" neodymiums over them. I even did this once in a repair, when a pickup was apparently manufactured without any gauss on one of the pole pieces. I don't recommend messing with any pickups you like, because you'll never get it back where it started, and it is a crude way to do things.) Those should be insulated away from other magnets, especially powerful magnets. You can't "shield" magnetism, you just have ensure that they keep their distance. Wrapping them up in foam packing, paper towels, or something else is always a good idea. Sticking to a metal surface, in this case probably low carbon steel, probably wouldn't hurt the magnet, but I don't know that for sure. I think it would take an incredible amount of magnetism to reorient a ceramic magnet, I'm not sure if you could do it with a comparably sized neodymium.

Other than that, I like to make sure they're sealed up so things like stray steel wool can't touch them, and to protect the more frail parts that might be otherwise protected by the guitar itself, like the wires going to the eyelets. For that part, a ziploc does just fine.

I just remembered a story that might be relevant.

Years ago in a pickup making community one of the high ups at Seymour Duncan told a story about how he had a JB in a junk drawer for years, not really protected. For whatever reason, he pulled it out and installed it in a test guitar and liked how it sounded. He brought it into work and everyone else liked it too. The pulled it apart and the magnet had degaussed in a rather strange way (strong on one end, less so on the other I think) so they duplicated it for some limited run of "aged" pickups as that line's particular flavor of the JB.