Step 1: Materials
A map of the area you want to immortalize in string
It's all pretty obvious, really.
Step 2: Trace the Map
Then I imported the map to an image manipulation program (Illustrator probably, or Photoshop, but you can use anything), created a new layer and traced around the border. Then I added a heart where I live and deleted the map layer, leaving me with a clean outline.
Next I split the image into pieces that would print easily on 8.5x11 paper, printed it out, and taped it together!
Step 3: Nail it
Next, place the map on top of your board and start nailing away! I placed my nails about 1/2" apart and wish I had put them closer together. Which is hard because my fingers aren't much thinner than that, and holding the nails in place was tricky!
Don't pull too hard on the string as you're wrapping your nails. My string kept popping off the nails, and even popped nails out of the board until I learned to loosen up a little!