I have to confess. I think up to this point this palm tree is the most involved thing I have modeled. It turns out adding all the leaves and getting them in the right spots was not as easy as I thought it was going to be.
It was easy enough to copy the leaves as I needed them. It was much more involved when it came to getting them in place as I wanted them to match up with the sticking out bits on the top of the trunk. That took a lot of tweaking to get it in about the right spot and then rotated to match up with the bit sticking out. I did the bottom layer first and that seemed to go ok. Then I decided to add the second layer and this is where I discovered things were a bit more complicated than I anticipated.
I ran into a bit of an issue with penetration. When I put the second layer of leaves in some of them had frond bits penetrating the leaves below them. In real life, this wouldn’t be happening, the frond bits would just bend. I haven’t done any testing to see if the physics engine that works with particles would do any good here so I just made adjustments to the leaves and fronds themselves. I did some rotating to put a little more distance between the two layers. I also found that I needed to make the stems of the leaves longer. First I did this on the second layer and then I found I needed to do that to the bottom layer as well. It was then a given that I would make those adjustments when I worked on the top layer.
When I decided to make the stems longer I added some edge loops to each stem so that I could do a little more adjusting to it. Some of them I just made longer and some I added some bend in the stem by rotating at an edge loop and then transposing the position a bit to smooth things out. Sometimes there would be objects that were making it difficult to see what I was adjusting and so I would have to hide a few leaves, or the trunk for a moment so I could see or select something. 
One of the nice side effects of having to adjust the leaves in such a manner is that it makes for more variety than just the four leaves I started with. Some had to be adjusted, some did not, and that makes more of them unique.
When I added the top layer, I found I needed to rotate the leaves so they were much closer to vertical in order to get the illusion of fullness and height. Because this put them closer to each other there was a bit more of the minor adjusting to be done with the fronds. By the time I got to the top layer, seeing around the other leaves to get be able to 
get one in place was very much like trying to look through those leaves at a real tree.
Once all the leaves were in place I found that the tree looked a bit small and squatty so I stretched the trunk a little for better proportion. I could probably make it still taller, however, then it might mess up the balance of the whole card so I think I will stick with this.