The 27-year-old actor, who will take over the lead role on the upcoming fifth series of Doctor Who, told SFX that he is pleased with the way his alter ego has turned out.
"What's interesting about this particular Doctor's look is that it's going to constantly evolve," he said. "Steven [Moffat] is very keen that he's a man who gets up in the morning and wears clothes because it's cold."
Smith added: "He's not only defined by one thing. If you look at every Doctor, every Doctor has something, and I have a bow tie.
"As always with this show you're dealing with history, and you go, 'Oh, I can't have a scarf because Tom Baker had a scarf, I can't have a pair of converse...' but I'm pleased, because the costume has come out of my personality, and it feels right on my body and my frame."
> Moffat talks Smith's first 'Who' scene