I did a safari baby shower cake. I had palm trees on it made from large pretzel rods. They were frustrating to do at first, but by the time I did the 4th one, I felt like I knew what I was doing.
I used the Wilton leaf fondant cutter to cut out the palm leaves. I let them dry on a paper towel cardboard cut in half. (Flower formers work, too.) Once they were dry/hard, I made some green royal icing, and put a big blob on parchment paper(about the diameter of a silver dollar-be sure to mound it up a bit). I began sticking my leaves in the royal icing, sticking cotton balls inbetween layers to help give shape and fullness. Once they were dry, I put a blob of royal icing on the end of my pretzel rod, and attached the palm leaves piece. To "hide" the place where the two were attached, I used the leaf tip, and made royal icing leaves underneath the fondant leaves. This helped to give the palm leaves more support, too. I also put some inbetween leaves and on the very tip-top to hide the center of the palm leaves. I think it helped it look a little more realistic.
Here is a link to the pic of my cake: Hope this helps you some... Good luck!