Compostion and subject exposure are okay although not sure what you shot against or whether the background was lit separately as the background is over exposed to the extent it's wrapping back on the subject, most notably the right side of his face and his boots.
Also would help if there was ground shadow to prevent the floating on white background look.
As Andy said, background a bit too bright.
Thanks for the replies. The background is a muslin sheet hung on the curtain pole over a set of french doors in my living room as I havn't yet bought a stand. Out of the twenty pics I took none of them were as sharp as I'd of liked, could this have anything to do with glare coming from the background, or something totally different?
With light spilling over from the background, you'll lose a bit of contrast. Less light on the background, or move him further away from it (if you have the room) would help.