Big thanks to Tim Anderson for taking the action shots.
Step 1: Cut Your Stencil
The low-tech version would be to print out the design in reverse, tape it to cardboard, and go nuts with a box cutter or Xacto blade. But that's another story for another Instructable and you're smart and clever enough to figure it all out, right?
After you've made your cuts, put all the pieces back together. This is how you're sure the placement is right.
Step 2: Get Some Pieces of Wire
Step 3: Make some wire bridges
Step 4: Tape 'em Down
OK, this is duct tape. Duct tape on cardboard. Duct tape that is holding wire onto the cardboard. I'm sure you're not even reading this. Absolutely positive. Crap, I need some more wine.
Step 5: Holy crap! It's holding!
Step 6: Stick It, Spray It
Oh yeah, then spray it with some spraypaint. Be smart and get a can that isn't about 40 years old that you found in the back of a closet. But if you're gonna make something to put up online, then grab whatever. These small pictures hide the gruesome details.
Step 7: Enjoy Your Stencil
This is one method, there are others. I made this method up myself, but I'm sure I wasn't the first by a long, long shot.
This is one design of infinite possibility. Copy it from a source like I did here as an example or make something new. New is better.
Push yourself. Post your own efforts in the comments or simply spread it to others around you.