I know how you feel about writing on cakes, I came up with a great idea that I thought was something original, then I read about it on here somewhere, guess I wasn't as original as I thought, BUT it works so that's the main point.
I go to the trusty pc and find a font I like, print it out the size you would want to write on the cake. Tape the paper onto a flat surface ( I use my cutting board) and then tape waxed paper over top, rub just a tiny bit of crisco on (just enough to make it look glossy when tilted) and then take royal frosting and ''trace'' your words. Let dry and they peel right off, VOILA, beautiful writing!!
And the best part is being able to pick it up and move it if you don't like where you place it on the cake the first time. If you have a good crust on your cake you won't have any boo boos to fix!!
Happy cake baking!