It's not my favorite, but I may as well document the idea. The tree in the top image is made from all the same color, but there are alternating colors in the bottom image, for deomnstration purposes... There are 12 large leaves in a circle, but this circle weaves over-under-over-under... so all the dark green middle sprues (B, as seen in this this image) go below all of the lighter green leaves' middle sprues (B). It makes a leafy circle, kind of a like a crown. On top of the trunk there is a pole sticking up, and there are five leaves woven together, sticking onto the pole. Then you can stick the leafy crown over the leaves on the pole, and it will spring into place and hold.
See other ideas in this set.