Remove the peels from the lemons and/or oranges. Time the extra pith from the sides of each peel, then slice into ¼" strips.
Boil the peels in water for 15 minutes. Drain the peels, then rinse them. (This proccess can be repeated another time to further reduce the bitterness from the pith.)
Weigh the citrus peels. Heat that weight of sugar and water each with the citrus peel to a low simmer (if the peels weigh 100 grams, use 100 grams of sugar). Continue cooking until the water has evaporated.
Spread the peels out to cool completely before tossing with extra sugar to coat.