In a small saute pan toast the anise seed for about 30 seconds or until fragrant. Remove from heat.
Cut the skin off an orange with a sharp paring knife and then carefully cut off as much of the white pith from the skin as possible. Cut the same orange in half and squeeze the juice out of it.
Slice the ginger into 1/8 " pieces and rough chop the mint.
Combine sugar and water in a small heavy bottomed pot. Bring to a low simmer and stir until sugar dissolves. Add in the orange peel, orange juice, mint, ginger pieces and toasted anise seed. Reduce heat to low and let simmer for 10 minutes. Turn off heat and let syrup steep as it cools.
Strain through a fine mesh strainer and store in a clean container in the refrigerator.
For the soda I usually combine about 2 Tbsp of the syrup with 12 oz soda water, but you can adjust to your personal taste.