Using the magnets from a dead 3.5" HDD and a piece of wire, I made a super strong refrigerator magnet. When I say super strong, I mean this thing will hold up anything I ever wanted to put on my fridge.
Step 1: Find an Old Hard Drive, and Take It Apart
For this job you'll need some torx drivers of various sizes (5.5, 8, and 10 were what I needed). Just keep taking out screws and peeling back labels until it's all in pieces.