You should emphasize your palm tree with some up-lighting that will create a dramatic effect in the evenings. Placing various sized stones around the tree will help fill in underneath the tree, and you can landscape around the tree with some succulent plants in between the rocks.
Palm trees are easy to decorate with because they are so tall, take up virtually no space, and make any landscape appear lush and more tropical. Try planting some smaller, flowering shrubs around the base.
I love seeing materials that remind me of everything palm trees represent, to me, as landscaping around them. For example: sand, aged wood planks as pickets, etc.
Other green plants of similar textures i.e. appearing like they came from the area could be planted around it, or you could use a pretty mulch and rocks to landscape.
