@bertwert - I trust Yuri is going to come back with some helpful tips.
In the meantime, whilst I'm no portrait photographer... It's a perfectly decent shot, however:
I assume this was taken at a point in time within other activities, and wasn't something you could prepare for (time of day, lighting, etc.). I'm therefore also assuming that the DA40XS is what you had on your camera at the time? Finally, I assume you wanted to include that beautiful background of both the rocky outcrop and the water as part of the environmental context for your shot?
If those are accurate assumptions, I might have chosen to take the shot in landscape orientation... placing your friend's head and shoulders in the lower left third of the shot, and stepping back until you were able to get a little sky, all of the rocky terrain and perhaps a little of the water fitted in between the top and bottom of the frame. I might even have dropped the camera a little and pointed up towards your friend's face.
These are just my opinions, and they wouldn't necessarily result in a better shot - merely different, and it's how I might have been thinking in the situation