I don't think people realize how many pictures you have to take of a baby in order to get maybe one or two really good ones. Frederick can smile, but he isn't going to smile unless he damn well feels like it, which is usually right after a nap, a diaper change, some milk, and a burp (in that order). Then, and only then, he'll gift you with the most dazzling smiles you can possibly imagine, his eyes brightly gazing into yours, cooing sounds emitting from his mouth, and for about three minutes, everything is perfect in the world.
Per my suggestion, this was also a spontaneous shoot, as he had woken up from his nap in a particularly nice mood, so I grabbed a pair of overalls, stripped him of his uniform sleeper (fourth kid, sorry, buddy), and that's when the trouble began. Fortunately we got him to cooperate somewhat on the floor, and after a bit, we even managed to prop him up in the tiny armchair. And that was where we got the magic, in the last image below.
Frederick is about 3 1/2 months in these pictures (again, fourth-kid syndrome means we never know EXACTLY how old he is at any given moment in time).