Step 1: Determine measurements and print out an offset for the template
The formula for the offset is (bushing size - router bit size) / 2 = offset. The bushing I used is .4375". The bit was .25". The offset is .09375" (fraction is 3/32").
In Photoshop open or make a two tone graphic. This graphic of a hop is about as complex as you can get. Just remember that the router bushing is almost a 1/2" wide and the blade is a 1/4". Any tight inside corners might start to disappear when cut. Look at the hop stem in the test cut for instance.
-Note the resolution of your graphic. (From the menu Edit>Image size. There is field that tells resolution)
-Multiply resolution by the offset. Mine is 72 dpi x .09375 = 6.75. This is your pixel offset.
-With this graphic open and sized to the correct size you, select the white space. From the menu click Select>Modify>Expand. Put your "pixel offset number" in the dialog that comes up. It will expand the selected area. You can either fill the selected area or the inverse selected area with another color as I did here with red. Print this out.