Was hast du in den letzten Sommerferien gemacht?

The key to a question like this is making sure to include multiple tenses, even if the question only expressly hints at one. This should be an opportunity to show your knowledge of the past perfect and imperfect, the exclusive uses of sein/haben as auxiliary verbs, as well as using the future to express conditionals - ich möchte nächstes Jahr mehr Sport während den Ferien spielen etc.