There's more than one way to skin a cat, or so the saying goes. I'm sure there are other ways to make Thomas' face, but this is my technique. You can find these tools at Hobby Lobby, Joann's, or Michaels. They're also available on Wilton.com.
You'll want to aim for the center when forming the nose. So, start with you tool just below where you imagine the center should be.
Lift with finger and carefully form a little hole, insert a small ball of fondant into the hole, then close.