What plants could I use to give my garden a Middle Earth feel?

I love the lush, exotic trees and flowers that you see in the LOTR movies, or read about in the books. I’d like to achieve a similar sense of awe with my garden, which will be planted in front of my house, but I’m unsure of which plants offer the greatest visual impact, knowing very few varieties of plants myself.

It may help to know that I live in Memphis, Tennessee, and that the gardening zone is 7A.