Buy toys second-hand, join a toy library, choose wood, fabric or metal for new purchases, and pass toys on when outgrown. Ask relatives for experiences or contributions rather than plastic.
A family buying a dozen fewer new plastic toys a year avoids around 2 kg of mixed, unrecyclable plastic. The Ellen MacArthur Foundation's upstream-innovation hierarchy applies: eliminate first, then reuse, then substitute the material.
The catch: wooden toys are pricier new and some are finished with plastic paints; second-hand plastic toys keep existing plastic in use, which is fine, as long as they are safe and complete.