Hi, Rick. The way I do it is to get either a Rotozip tool or a Dremel tool with a chuck and, in both instances, use the Rotozip bit for ceramic tile. Cut a little proud of the line since it is difficult to cut real true this way. After you have made the cut, use an abrasive drum to sweeten the cut. I put a 2x2" drum in my drill press that has an oak board with a 2-1/8" hole bolted to the table. This gives you a nice flat surface to work on while grinding the tile right up to the line. You might be able to hand hold the drum in a drill motor and move the tile but the drillpress is a lot easier.
In any case, this will be very dusty operations. Be sure to wear a dust mask or better and be ready to vacuum everything in the house/shop when you are done. I did as Detroit Red Wings logo in tile and used it as the bottom in a serving tray. Came out great and the pieces I was cutting were small and had to be precise. I'm not saying that some of the less than 1/2" on a side triangles didn't fly around the shop pretty well, but those would have been tough no matter how I did them. I still run across one every so often more than a year later. This is also a good excuse for you to buy the Rotozip. Everybody already has a Dremel, or should.