I was making up a box for workshops. I like to be able to grab and go. There are pin magnets on the market, but they are expensive and if you drop one, it tends to fall apart. Ask me how I know that.
Linda sent me a fabulous chocolate chip cookie one year and I kept the tin it came in. For a long, long time it held my postage stamps. I asked Karl to help me out and he grabbed a large magnet off the fridge and glued it inside the tin.
Then I threw in some pins and I now have a pin tin that travels. Anyone can make these and they are a lot cheaper than the magnets.