I've seen these floating around on Pinterest for a while and saved it for later. My fiancé has 2 magnets that have worked for a while. But lately he's been getting graduation and baby announcements from cousins that have been getting little too heavy for those two magnets. So while I was house/petsitting for him, I determined to finally make some and get those pictures nice and spread out so you can actually see all those beautiful people.
I followed the tutorial on Not Martha, though I tried it first with flatter magnets that come in the tape roll and have a sticky side. I didn't want them sticking out so far with the bigger ones she used. They stuck on great. And then I tried to use them to hold up a picture and they slid all the way down off the fridge.
Back to the store I went, purchasing the big ones. I stuck them on with tacky glue and let them sit overnight. You have to make sure they're not sitting close together because the magnets are really strong and they start sliding toward each other while the puddle of glue is drying!
Overall, very easy. Get a bag of clear, large, flat bottomed marbles from Michaels. They're by the floral foam. Get a package of thick, circular magnets, from the very back of the store, just behind the wood projects. Cut out some scrapbook paper in the shape of the marble, glue on (tacky glue worked fine) to the flat side of the marble, and let dry. Then glue on the magnets with tacky glue and let sit to dry. I wouldn't use the magnets until the next day, just to make sure they've had enough time to set.