Off the bat, I'd say this is a really great photo on the whole. Whilst I'd be inclined to say that the composition could have been moved just a tiny bit to the left - since I've seen some of your other photos, I'm certain that you must have comp'd this image like this for a reason. That said I can still understand your choice of a more central composition.
The overall colour presentation is good, with your hair colour, chosen top colour, blue eyes and the green in the background all working harmoniously together, and providing a good range of contrast, whilst still complementing each other.
The DOF blur you have used does a good job of maintaining focus on you in the foreground, but fades into focus smoothly so that the defocus doesn't come across as harsh and too contrasting to what is in focus. This is especially true on the edges of the subject.
I would say that the lighting in this image works well, and the bright light on the right adds that special X-factor to the photo, without it I think the image would be slightly less special. Your camera-side lighting is also excellent, and no harsh shadows can be seen creating unnecessarily dark areas, particularly on the face. Great lighting.
Lastly, but most importantly, the subject shows a good deal of personality, both in the eyes, and the eyebrows. The corners of the mouth add a degree of interest as to what the subject may be thinking, or what kind of personality they may have. The lack of parallels in the pose, and the facial features, as well as the head tilt creates a subtle dynamism that makes the overall impression of the photo pleasing. The natural hair swoop also adds extra life to the photo.
Admittedly, I'm not sure if critique would be able to help you very much at your level of photography. Clearly you understand how to use your camera well, and what elements make a good photograph, especially in terms of chosen aperture and lighting set-up.