Royal "Prep" Work
It seems that many royals do interships at various diplomatic organizations as part of their preparation for their future roles. For instance,
In October/November 1999, Crown Prince Haakon was a member of the Norwegian delegation at the UN General Assembly.
While Crown Princess Victoria was studying at Yale, she did two interships at the UN and one at the Swedish Embassy, among other things.
What other "prep" work have royals done?