C&C per req:
1. Very good lighting, especially for window lighting. I'll ignore the background based on your statement that you were practicing, but the image does have one major issue and that's focus. A 1.4 lesn is great; lots of light, and very shallow DoF. In this case, too shallow. I can't quite pinpoint the point of focus, but all of the image I see is soft leading me to believe that it may have been his finger tips that were focused on. Always make sure you know where your camera is focusing, and as a rule, if only one thing is going to be focused, make it the eyes. Also, try and avoid composing/cropping such that limbs are "cut" at joints, such as the knuckles of his left hand; looks rather like an amputation.
2. Again, very soft focus; it looks in this case like you focused on the right hand, as the fingers seem quite sharp. The conversion isn't bad, but a little over-exposed. I'd suggest toning the highlights down 1/2 - 2/3 stop
Just my $00.02 worth - your milage may vary
~John