Curitiba,
Nice shot! I am a photographer myself, and I really like what you've done with this shot. You've managed to capture the wafting smoke, and I like your shallow depth of field. One question: what IS the object in the back?
My only critique of this shot is that the left edge of the object in the back is a little hot (i.e., the highlight on the edge of that object is too bright IMHO, and pulls my away from the cigar and box towards that bright little corner. Also, if you feel that the object in the back is important to the composition of your shot, you may wish to close down the lens just a bit for a little more depth of field, and to allow us to get a better idea of what the object is.
Really excellent shot, excellent lighting and composition. What was your light source, natural light? Keep up the great work!
Cheers,
Justin