We're in the process of laying ceramic tile in our entry and hallway. At Home Depot we've picked up a joint spacer specifically to match up different floorings. We have some carpet that will be up against the tile. It comes in different colors and makes a clean line. Part of it is placed under the tile. The areas that we've finished look fine. Good Luck!
PS- They have them for tile to vinyl, tile to carpet, tile to wood.