Using a paring knife, make 6 slits along curve from top to bottom of each citrus fruit, cutting through peel but not into fruit. Using your fingers, gently remove peel. Reserve fruit for another use. Slice each piece of peel lengthwise into 1/4-inch-wide strips. Using a paring knife, remove excess pith from each strip and discard.
Place strips in a large saucepan, and cover with cold water. Bring to a boil, then drain. Repeat twice.
Bring sugar and water to a boil, stirring occasionally until sugar dissolves. Stop stirring. Wash sides of pan with a wet pastry brush to prevent sugar crystals from forming. Add strips to boiling syrup, reduce heat to medium-low, and simmer gently until strips are translucent, about 1 hour. Remove from heat, and let strips cool in syrup. (Strips in syrup will keep, covered and refrigerated, for up to 3 weeks.)
Using a slotted spoon, transfer strips to a wire rack placed on a rimmed baking sheet. Wipe off excess syrup with paper towels, then roll strips in sugar. Arrange in a single layer on a wire rack, and let dry for at least 30 minutes.
Sugared peels will keep, covered at room temperature, for up to 2 weeks.