Fly stitch is great for creating leaves, geometric details and neat, uniform V shapes.
Here's how ya do it!
Bring needle up at A and re-insert at B.
Pull through to the back of you work, leaving a small loop (photo one).
Bring needle up at point C, making sure it goes through the loop you have created (photo two) and pull your thread all the way through to the front.
Insert your needle on the other side of the loop, very slightly below point C, and slowly pull snug (photo three).