I made these magnets in less than ten minutes using the Naturally Serif Alphabet for the Big Shot. Since these letters are Bigz dies, they can cut over 70 different types of materials (see the most current list here). Including magnet! I used the same type of magnets for this that I did for my Build A Bear Workshop paper doll tins–from www.fridgedoor.com.
You can decorate your letters any way you like–I punched out hearts with the Heart To Heart punch, attached them with mini glue dots, and then coated them with Crystal Effects, so they're good and sturdy. And shiny. Love shiny.