The thing with TV and filming is the timing is all faked anyway. You do it so many times, from so many different angles. You never really do it all in one go anyway, so they just fix it all in the edit.
Smiles come naturally to me, but I started thinking of them as an art form at my command. I studied all the time. I looked at magazines, I'd practice in front of the mirror and I'd ask photographers about the best angles. I can now pull out a smile at will.