kids: reassure for sure!
adults: well it depends on the degree of damage caused by the fracture. If undisplaced or uncomplicated, then the best is figure of 8 bandage. You won't have both this and an arm sling on the test cuz its controversial.
But if you have neurovascular compromise (bruit over the clavicle region), then it's angiogram (to identify the degree of vascular compromise) followed by open reduction and internal fixation (ORIF) with a plate and screws.
Just learnt from my Uworld notes that Mid clavicular fractures can be managed with brace/figure of 8 bandage (if without complications)
Most Distal 1/3 fractures need ORIF with plate and screws for fear of displacement and non-union.