I put together two fans, one for either side of the head. I plan to hide them under the hair a bit, but until I have the hair done I won't know for sure what that will look like.
Anyways I got the instructions on how to make these fans from Matrices.net
Here's all the stuff to make one fan: a soldering iron and solder (the pink thing is a de-soldering bulb for picking up mistakes), one 9-volt battery, a 9-volt battery cap with wires, an on/off toggle switch, and one small computer fan. Not pictured (because its transparent and impossible to photograph well) is some clear heat-shrink tubing. Oh and some plastic canvas, yarn, and electrical tape. I already had the soldering supplies, and the rest of it cost me about $10 total per fan.
I didn't take pictures of every step because you can get that at Matrices. I don't even know why I bothered taking this one, lol. Just to prove that I made the thing myself I guess. Oh one thing, Matrices didn't say anything about the yellow wire on the fan. The fan came with this little connector thingie that connected the three wires to just a red and a black. So I used that connector, so that I was only dealing with the red and black.
Anyways this is a finished fan, attached to a piece of plastic canvas. I made two identical units like this.