Select 24 of the best-looking raspberries.
Thread 3 to 4 berries on each of 6 to 8 thin wooden skewers.
Lay skewers on a flat pan and put in freezer until berries are firm, about 45 minutes.
When remaining raspberries are thawed, press through a fine strainer into a 4- to 5-quart pan; discard seeds and pulp.
To pan, add juice and slices of orange and lemon.
Stir over medium heat until steaming, 10 to 15 minutes.
Ladle juice (no slices) into 6 to 8 tall glasses; add a swizzle to each