Paper Mache Cones
White Paint Pen
This is one of those super easy mode crafts. You just paint the outside of the cones in cute colors (might need more than one coat). Once it's dry decorate the outside with the paint markers. I had my little one help as much as he had the patience for (which, you know, was about 3 dots).
The cost of supplies was under $10, and this kept him amused for at least five minutes, which is like five hours for a one year old so I'd call this project a success. The fact that the "toy" I've created can also double as a decoration is an awesome bonus.