This is the basic form of the three largest trees in the Pool Party. Here's how I made it. See the comment below for instructions and links to larger images.
There are other methods of making trees with this technique. I'll talk about some of those later.
I had a request to show better how to make these trees. I do hope that this is easy to follow.
Edit: Here is a link to a photo with small leaves woven: www.flickr.com/photos/eilonwy77/7238222882/in/photostream
See complete set for other examples: www.flickr.com/photos/eilonwy77/sets/72157629804759804/