Step 1: Seat subject in front of lovely background and get him prepared for the shot.
*ahem* Prepared for the shot?
Step 2: Snap your lovely picture.
Uh....focus? Did I forget to mention focusing the camera?
Eh....if subject looks up at camera while sitting in front of lovely background and you've got him in focus, just snap the picture,
his shirt got dirty before the photo session so you know you weren't going to send it out anyway he's so adorable he looks great smiling or not!