I love this tool, and bought several disc that I felt I would get the most use out of, and then I also purchased the disc maker.  The trick to using this is to pay attention to the little + signs on either the right or the left of the runner.   You need to place this + sign where you want your printing to
"Begin"   If you are going to run the runner to the left use the left +, if you are going to run your runner to the right, use the right +, and you should have NO problems with it starting to print where you want it to  as long as you line up the + sign .  REMEMBER that prior to moving the runner, you must press down on the green print button, hold it and wait for the small "P" to show and then move your runner to the left or right. 

I would also recommend that you take a blank piece of your 12 x 12 paper and print out each saying so that you know how long each saying is.  Some are quit long and need alot of space.  I use this sample to line up my pages that i am going to print something on so that it is perfectly centered where I want it and I know exactly where to place the + sign.

Have fun and get creative with it.