Micro clamps can be made cheaply from a package of close pins purchased from the dollar store. As you can see they can be made in an assorted shapes and sizes to meet your custom needs.
You can use a belt sander, disk sander, Dremel or whatever you happen to have. I have even used a scroll saw to cut various shapes and sizes. My preferred method is still to use a belt sander with a course grit but that is only because it is quick and easy.
These clamps can be made in a minute or less and not only do they come in handy for various projects, I have also found them to be in demand at craft and trade shows. I usually sell them as an assorted package of 4 for a dollar.
They can be used for various projects such as holding projects while I'm painting them, or holding parts together as they are being glued. Uses are many, and if you know a crafter in need of clamps, they make a great gift.
This is a short video of how I make my micro clamps from cloths pins.