The start of the tween years, nine years old, is a sweet spot between curiosity and growing independence, making it a fun, though sometimes tricky, age to buy for.

Kids at this age are up for a challenge, whether that means trying a trickier craft set, playing a more complex game or stepping up their sporting interests. Pitch a gift right and you’ll not only get the whoop of joy when they first receive it, but something that will hold their interest and help them develop their skills, interests and hobbies over time.

How I selected

Various gifts and toys were sent to nine-year-olds for testing and feedback. Photograph: Zoë Phillimore/The Guardian

As an experienced toy tester, I have dedicated a lot of my career to observing children play. I’ve worked in schools as a teaching assistant and in children’s publishing, where knowing what makes children tick is essential. I also have three children of my own, so I understand what works on home turf once the gift-opening frenzy is over.…