I picked up a $3.99 bunch of greenery in my supermarket and stitched love into the leaves.
To make this work you will need a thick leaf - a thin leaf won't do. The leaves I purchased were a standard filler foliage that is commonly used in arrangements.
Using a pen, gently draw out your design on the leaf. I used red embroidery thread and a back stitch. I found that holding the leaf up to the window backlit it and allowed me to see where to pierce the leaf from the back.
Keep your embroidered branch of leaves in a vase of water and it will do great. Also, you could preserve it by pressing the branch in a book.