[Nostrafus]

Get 20ga and 32ga enamel coated copper wire, and a small 1/4" dowel rod.

Use the 20ga wire as the main spool, unwrap the wire, lay it flat and take out the 32ga wire, wrap it around the 20ga 2-3 times every 1/8" and cut the spikes down to size (roughly 1/16") then when it's all done (should take a few hours) Get your 1/4" dowel rod, and wrap it as close together as you can, and slide the wiring off the dowel rod, this will give you the rolled look of WW2 barbed wire.

As for the wood holding the barbed wire, you could probably go with a ice cream pop stick.