- Any paper clip (This was done with regular uncoated non-hex clip paper clips)
- Jeweler's needle nose pliers (rounded tips for bending coils and stuff)
- Small regular pliers (flattened gripping surfaces)
- Lots of determination and a steady hand
The above image shows roughly the belt buckle shape. You want to take your jeweler's pliers to do the bending, by holding the region where you want the bend to be with the tips, then bending the paper clip around it. You want to form a shape that looks like a window, as illustrated by the top drawing. It should look like a window, or a blocky "8". To cut off the excess material, you simply need to score or notch where you want it to break off, then simply cold work that region. The notch will grow as you cold work it, eventually leading to a fracture.
The trick to getting the buckle to work is to bend the two halves at an angle, illustrated by the bottom part of the drawing shown above. With the buckle bent this way, the belt strap or whatnot will have to overcome more friction to become undone. This will allow you to put belts around curved objects without needing the little pin and notches used to hold a belt in place.
Here's a demonstration of the paper clip belts in use on the Kris Mage.
I've used paper clips to do the loops on the dress where I fed the ribbon through. Below that, there are two belt buckles that hold pretty well by themselves. You'll need to sew or attach your belt to the middle section to complete your belt.
I'll be experimenting with more belt buckles as I upgrade my TF2 dolls with better belt materials. Cardboard isn't cutting it, nor are they up to standards.